Intelligent patching systems and methods using phantom mode control signals and related communications connectors

ABSTRACT

Communications connectors are provided that include a plurality of input ports, a plurality of output ports and a plurality of conductive paths. Each of the conductive paths connects a respective one of the input ports to a respective one of the output ports. The conductive paths are arranged as a plurality of differential pairs of conductive paths that are each configured to carry a differential signal. These connectors further include a control signal input circuit that is configured to capacitively couple a phantom mode control signal onto at least a first and a second of the differential pairs of conductive paths.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Patent Application Ser. No. 61/435,248, filed Jan. 21, 2011,and to U.S. Provisional Patent Application Ser. No. 61/475,251, filedApr. 14, 2011. The entire contents of each of these applications areincorporated by reference herein as if set forth in their entireties.This application is related to U.S. patent application Ser. No.13/111,112, and to U.S. patent application Ser. No. 13/111,015.

FIELD OF THE INVENTION

The present invention relates generally to communications systems and,more particularly, to automatically tracking cabling connections incommunications systems.

BACKGROUND

Most businesses, government agencies, schools and other organizationsemploy dedicated communications systems (also referred to herein as“networks”) that enable computers, servers, printers, facsimilemachines, telephones, security cameras and the like to communicate witheach other, through a private network, and with remote locations via atelecommunications service provider. Such communications system may behard-wired through, for example, the walls and/or ceilings of a buildingusing communications cables and connectors. Typically, thecommunications cables contain eight insulated conductors such as copperwires that are arranged as four differential twisted pairs ofconductors. Each twisted pair may be used to transmit a separatedifferential communications signal. Individual communications connectors(which are also referred to herein as “connector ports”) such as RJ-45style modular wall jacks are mounted in offices, conference rooms andother work areas throughout the building. The communications cables andany intervening connectors provide communications paths from theconnector ports (e.g., modular wall jacks) in offices and other rooms,hallways and common areas of the building (referred to herein as “workarea outlets”) to network equipment (e.g., network switches, servers,memory storage devices, etc.) that may be located in a computer room,telecommunications closet or the like. Communications cables fromexternal telecommunication service providers may also terminate withinthe computer room or telecommunications closet.

A commercial data center is a facility that may be used to run thecomputer-based applications that handle the core electronic business andoperational data of one or more organizations. The expansion of theInternet has also led to a growing need for a so-called “Internet datacenters,” which are data centers that are used by online retailers,Internet portals, search engine companies and the like to provide largenumbers of users simultaneous, secure, high-speed, fail-safe access totheir web sites. Both types of data centers may host hundreds, thousandsor even tens of thousands of servers, routers, memory storage systemsand other associated equipment. In these data centers, fiber opticcommunications cables and/or communications cables that include fourdifferential pairs of insulated conductive (e.g., copper) wires aretypically used to provide a hard-wired communications system thatinterconnects the data center equipment.

As noted above, the communications cables and connectors in conductivewire-based communication systems that are installed in both officebuildings and data centers usually include eight conductors that arearranged as four differential pairs of conductors. Such communicationssystems typically use RJ-45 plugs and jacks to ensure industry-widecompatibility. Pursuant to certain industry standards (e.g., theTIA/EIA-568-B.2-1 standard approved Jun. 20, 2002 by theTelecommunications Industry Association), the eight conductors in RJ-45plug and jack connectors are aligned in a row in the connection regionwhere the contacts of the plug mate with the contacts of the jack. FIG.1 is a schematic view of the front portion of an RJ-45 jack thatillustrates the pair arrangement and positions of the eight conductorsin this connection region that are specified in the type B configurationof the TIA/EIA-568-B.2-1 standard, which is the most widely usedconfiguration. As shown in FIG. 1, under the TIA/EIA 568 type Bconfiguration, conductors 4 and 5 comprise differential pair 1,conductors 1 and 2 comprise differential pair 2, conductors 3 and 6comprise differential pair 3, and conductors 7 and 8 comprisedifferential pair 4. Herein, a differential pair of conductors may bereferred to simply as a “pair.”

In both office network and data center communications systems, thecommunications cables that are connected to end devices (e.g., networkservers, memory storage devices, network switches, work area computers,printers, facsimile machines, telephones, etc.) may terminate into oneor more communications patching systems that may simplify laterconnectivity changes. Typically, a communications patching systemincludes one or more “patch panels” that are mounted on equipmentrack(s) or in cabinet(s), and a plurality of “patch cords” that are usedto make interconnections between different pieces of equipment. As isknown to those of skill in the art, a “patch cord” refers to acommunications cable (e.g., a cable that includes four differentialpairs of copper wires or a fiber optic cable) that has a connector suchas, for example, an RJ-45 plug or a fiber optic connector, on at leastone end thereof. A “patch panel” refers to an inter-connection devicethat includes a plurality (e.g., 24 or 48) of connector ports. Eachconnector port (e.g., an RJ-45 jack or a fiber optic adapter) on a patchpanel may have a plug aperture on a front side thereof that isconfigured to receive the connector of a patch cord (e.g., an RJ-45plug), and the back end of each connector port may be configured toreceive a communications cable. With respect to RJ-45 connector ports,each communications cable is typically terminated into the back end ofthe RJ-45 connector port by terminating the eight conductive wires ofthe cable into corresponding insulation displacement contacts (“IDCs”)or other wire connection terminals of the connector port. Consequently,each RJ-45 connector port on a patch panel acts to connect the eightconductors of the patch cord that is plugged into the front side of theconnector port with the corresponding eight conductors of thecommunications cable that is terminated into the back end of theconnector port. The patching system may optionally include a variety ofadditional equipment such as rack managers, system managers and otherdevices that facilitate making and/or tracking patching connections.

In a typical office network, “horizontal” cables are used to connecteach work area outlet (which typically are RJ-45 jacks) to the back endof a respective connector port (which also typically are RJ-45 jacks) ona first set of patch panels. The first end of each of these horizontalcables is terminated into the IDCs of a respective one of the work areaoutlets, and the second end of each of these horizontal cables isterminated into the IDCs of a respective one of the connector ports onthe patch panel. In an “inter-connect” patching system, a single set ofpatch cords is used to directly connect the connector ports on a firstset of patch panels to respective connector ports on network switches.In a “cross-connect” patching system, a second set of patch panels isprovided, and the first set of patch cords is used to connect theconnector ports on the first set of patch panels to respective connectorports on the second set of patch panels, and the second set of typicallysingle-ended patch cords is used to connect the connector ports on thesecond set of patch panels to respective connector ports on the networkswitches. In both inter-connect and cross-connect patching systems thecascaded set of plugs, jacks and cable segments that connect a connectorport on a network switch to a work area end device is typically referredto as a channel. Thus, if RJ-45 jacks are used as the connector ports,each channel includes four communications paths (since each jack andcable has four differential pairs of conductors).

The connections between the work area end devices and the networkswitches may need to be changed for a variety of reasons, includingequipment changes, adding or deleting users, office moves, etc. In aninter-connect patching system, these connections are typically changedby rearranging the patch cords in the set of patch cords that runbetween the first set of patch panels and the network switches. In across-connect patching system, the connections between the work area enddevices and the network switches are typically changed by rearrangingthe patch cords in the set of patch cords that run between the first setof patch panels and the second set of patch panels. Both types ofpatching systems allow a network manager to easily implementconnectivity changes by simply unplugging one end of a patch cord from afirst connector port on one of the patch panels in the first set ofpatch panels and then plugging that end of the patch cord into a secondconnector port on one of the patch panels in the first set of patchpanels.

The connectivity between the connector ports on the network switches andthe work area outlets is typically recorded in a computer-based log.Each time patching changes are made, this computer-based log is updatedto reflect the new patching connections. Unfortunately, in practicetechnicians may neglect to update the log each and every time a changeis made, and/or may make errors in logging changes. As such, the logsmay not be complete and/or accurate.

In order to reduce or eliminate such logging errors, a variety ofsystems have been proposed that automatically log the patch cordconnections in a communications patching system. These automatedpatching systems typically use special “intelligent” patch panels thatemploy sensors, radio frequency identification tags, serial ID chips andthe like and/or special patch cords that include an additional conductorto detect patch cord insertions and removals and/or to automaticallytrack patching connections. Typically, these systems require that all ofthe patch panels in the patching system have these automatic trackingcapabilities and, in inter-connect systems, may also require that thenetwork switches include automatic tracking capabilities as well.

The use of common mode signalling has also been explored as a means forautomatically tracking patch cord connections in a communicationspatching system. As noted above, communications systems that useconductive wires as the cabling media typically transmit eachcommunications signal as a differential signal. As known to those ofskill in the art, differential signalling refers to a technique wherebyan information signal is transmitted between devices over a pair ofconductors rather than over a single conductor. With differentialsignalling, the signals transmitted on each conductor of thedifferential pair have equal magnitudes, but opposite phases, and theinformation signal is embedded as the voltage difference between thesignals carried on the two conductors of the pair. Differentialsignalling is used because it can reduce the impact that external noisesources may have on the transmitted signal. In particular, when signalsare transmitted over a tightly twisted differential pair of conductors,electrical noise from external sources will typically be picked up byeach conductor of the pair in approximately equal amounts. As theinformation signal is extracted from the differential pair by taking thedifference of the signals carried on the two conductors of the pair, theapproximately equal amounts of noise that are picked up by eachconductor cancel out in the subtraction process. As such, the use ofdifferential signalling can reduce the impact of external noise sourceson a transmitted signal.

In a communications system that includes multiple differential pairs percable/connector, such as RJ-45 communications systems, “common mode”signalling may be used to transmit one or more additional signals overthe cables and connectors. As known to those of skill in the art, acommon mode signal refers to the part of a signal that is transmittedbetween devices over two (or more) conductors that is extracted from thetransmitted signal by taking the voltage average of the signals carriedon the two (or more) conductors. Theoretically, a common mode and adifferential signal may be transmitted over a differential pair withoutinterfering with each other. In particular, since the differentialinformation signal is extracted from the differential pair by taking thedifference between the signals carried by the two conductors of thepair, the common mode signal is theoretically removed by the subtractionprocess. Likewise, the differential signal does not theoreticallyinterfere with the common mode signal as the differential signal addsequal but opposite signals that cancel out when the signals on eachconductor of the pair are averaged to recover the common mode signal.

In a communications cable that includes multiple pairs of conductors,multiple common mode signals may be transmitted along with thedifferential signals. By way of example, in a communications cable thatincludes two differential pairs (four conductors total), a differentialsignal may be transmitted over each differential pair and a common modesignal may also be transmitted over each differential pair for a totalof four transmitted information signals. Alternatively, the two commonmode signals may be replaced with a third differential signal that issimultaneously transmitted over all four conductors. In particular, thethird differential signal may be transmitted by transmitting itsnegative component as a common mode signal over both conductors of thefirst differential pair, and by transmitting its positive component as acommon mode signal over both conductors of the second differential pair.As the transmission of the negative component of the third differentialsignal adds the exact same signal to each conductor of the firstdifferential pair, the negative component of the third differentialsignal is effectively removed from the first differential pair duringthe subtraction process that is used to recover the first differentialsignal. The same is true for the positive component of the thirddifferential signal that is transmitted over the second differentialpair. Thus, in the above-described manner two differential pairs may beused to transmit a total of three differential signals. Although itcannot be characterized as a common mode signal, the third differentialsignal is comprised of two oppositely polarized common mode components,and thus it involves the use of common mode signalling. In order todistinguish signals such as the above-described third differentialsignal from both standard differential signals that are carried on twoconductors and from true common mode signals, herein differentialsignals that are comprised of two oppositely polarized common modecomponents are referred to as “phantom mode” signals.

U.S. Pat. No. 7,573,254 to Cobb et al. (“the '254 patent”) disclosespatch panels that include port identification circuits that transmitcontrol signals over a phantom mode transmission path to track patchcord connections. In an embodiment disclosed in the '254 patent, acenter tap inductor is used to inductively couple the phantom modesignal onto two of the differential pairs in a communications channel.U.S. Patent Publication No. 2010/0008482 to Tucker discloses techniquesin which phantom mode signalling is used to discover the patch panelconnector ports in first and second patching zones to which backbonecables are connected. U.S. Patent Application No. 2010/0244998 to Peytonet al. discloses injecting phantom mode signals onto a communicationscable in order to determine interconnections within a local areanetwork.

SUMMARY

Pursuant to embodiments of the present invention, communicationsconnectors are provided that include a plurality of input ports, aplurality of output ports and a plurality of conductive paths. Each ofthe conductive paths connects a respective one of the input ports to arespective one of the output ports. The conductive paths are arranged asa plurality of differential pairs of conductive paths that are eachconfigured to carry a differential signal. These connectors furtherinclude a control signal input circuit that is configured tocapacitively couple a phantom mode control signal onto at least a firstand a second of the differential pairs of conductive paths.

In some embodiments, the connectors are configured so that a positivecomponent of the phantom mode control signal is capacitively coupledonto the first of the differential pairs of conductive paths via a firstcapacitive circuit of the control signal input circuit, and a negativecomponent of the phantom mode control signal is capacitively coupledonto the second of the differential pairs of conductive paths via asecond capacitive circuit of the control signal input circuit. In somecases, the first and second capacitive circuits may each bethree-terminal capacitors. In other embodiments, a positive component ofthe phantom mode control signal may be capacitively coupled onto boththe first and second of the differential pairs of conductive paths via afirst capacitive circuit (e.g., a five-terminal capacitor) of thecontrol signal input circuit, and a negative component of the phantommode control signal capacitively coupled onto both a third and a fourthof the differential pairs of conductive paths via a second capacitivecircuit (e.g., another five-terminal capacitor) of the control signalinput circuit. The communications connector may be, for example, anRJ-45 jack that has four differential pairs of conductive paths, and thethird differential pair of conductive paths may be sandwiched betweenthe fourth differential pair of conductive paths in a plug contactregion of the conductive paths.

In some embodiments, the first capacitive circuit may comprise first andsecond capacitors. A conductive plate that is common to the first andsecond capacitors comprises a first electrode of each capacitor, a firstcontact pad comprises a second electrode of the first capacitor, and asecond contact pad comprises a second electrode of the second capacitor.In such embodiments, the input ports may be spring contacts, and thefirst contact pad may be configured to mate with a first of the springcontacts and the second contact pad may be configured to mate with asecond of the spring contacts. In some embodiments, the communicationsconnector may be a jack that is configured so that insertion of a plugwithin the jack causes transfer of the phantom mode control signal ontospring contacts of the jack.

According to further embodiments of the present invention, methods ofproviding identification information for a communications connector areprovided in which a phantom mode control signal is generated thatincludes identification information for the communications connector. Afirst component of the phantom mode control signal is capacitivelycoupled onto both of the conductive paths of a first differential pairof conductive paths of the communications connector, and a secondcomponent of the phantom mode control signal is capacitively coupledonto both of the conductive paths of a second differential pair ofconductive paths of the communications connector, where the polarity ofthe first component is opposite the polarity of the second component

In some embodiments, the phantom mode control signal may be a modulateddigital signal. The phantom mode control signal may be transmitted inresponse to detecting that a plug has been inserted into a plug apertureof the communications connector. The phantom mode control signal mayinclude a unique identifier that identifies the communicationsconnector. The first component of the phantom mode control signal may becapacitively coupled onto both of the conductive paths of the firstdifferential pair of conductive paths (e.g., via a first three-terminalcapacitor) and the second component of the phantom mode control signalmay be capacitively coupled onto both of the conductive paths of thesecond differential pair of conductive paths (e.g., via a secondthree-terminal capacitor).

In some embodiments, these methods may further include capacitivelycoupling the first component of the phantom mode control signal ontoboth of the conductive paths of a third differential pair of conductivepaths of the communications connector at the same time that the firstcomponent of the phantom mode control signal is coupled onto both of theconductive paths of the first differential pair of conductive paths ofthe communications connector, and may similarly include capacitivelycoupling the second component of the phantom mode control signal ontoboth of the conductive paths of a fourth differential pair of conductivepaths of the communications connector at the same time that the secondcomponent of the phantom mode control signal is coupled onto both of theconductive paths of the second differential pair of conductive paths ofthe communications connector.

According to further embodiments of the present invention, methods ofidentifying connectivity in a communications network are provided inwhich a phantom mode control signal that includes a unique identifierthat is associated with a connector port on a network switch istransmitted to a patch panel connector port over at least twodifferential pairs of conductors that are included in a patch cord thatconnects the connector port on the network switch to the connector portof the patch panel. A first component of the phantom mode control signalis coupled to a phantom mode control signal receiver via a firstcapacitive circuit included the patch panel connector port. A secondcomponent of the phantom mode control signal is coupled to the phantommode control signal receiver via a second capacitive circuit includedthe patch panel connector port. The unique identifier associated withthe connector port on the network switch is extracted from the phantommode control signal at the patch panel. The connection between theconnector port on the network switch and the patch panel connector portmay then be logged in a connectivity database.

In some embodiments, the phantom mode control signal may be transmittedin response to detecting that a plug has been inserted into a plugaperture of the connector port on the network switch. The firstcapacitive circuit may be a first capacitor having an input terminal, afirst output terminal and a second output terminal that is configured tocouple the first component of the phantom mode control signal onto afirst of the differential pairs of conductors that are included in thepatch cord, and the second capacitive circuit may be a second capacitorhaving an input terminal, a first output terminal and a second outputterminal that is configured to couple the second component of thephantom mode control signal onto a second of the differential pairs ofconductors that are included in the patch cord. The first component ofthe phantom mode control signal may have a polarity that is opposite thepolarity of the second component of the phantom mode control signal.

According to further embodiments of the present invention, “interposer”communications connectors are provided that include a housing, aplurality of plug blades that are mounted in a first portion of thehousing, a plurality of spring contacts that are mounted in a secondportion of the housing, and a plurality of conductive paths. Each of theconductive paths includes a respective one of the plug blades and arespective one of the spring contacts and one or more conductiveelements that electrically connect each plug blade to its respectivespring contact. These connectors further include a control signal inputcircuit that is configured to capacitively and/or inductively couple acontrol signal onto at least one of the plurality of conductive paths.

These interposer connectors may include eight conductive paths that arearranged as first through fourth differential pairs of conductive paths.In some embodiments, the control signal input circuit may be configuredto capacitively couple the control signal onto both of the conductivepaths of the first differential pair of conductive paths. In otherembodiments, the control signal may be a phantom mode control signal,and the control signal input circuit may be configured to couple a firstcomponent of the phantom mode control signal onto both of the conductivepaths of the first differential pair of conductive paths and a secondcomponent of the phantom mode control signal onto both of the conductivepaths of the second differential pair of conductive paths, where thepolarity of the second component is opposite the polarity of the firstcomponent.

In some embodiments, the control signal input circuit may be a firstcapacitor having an input terminal, a first output terminal and a secondoutput terminal that is configured to couple the first component of thephantom mode control signal onto the first differential pair ofconductive paths and a second capacitor having an input terminal, afirst output terminal and a second output terminal that is configured tocouple the second component of the phantom mode control signal onto thesecond differential pair of conductive paths. In other embodiments, thecontrol signal input circuit may be a first capacitor having an inputterminal and first through fourth output terminals that is configured tocouple the first component of the phantom mode control signal onto thefirst and second differential pairs of conductive paths and a secondcapacitor having an input terminal and first through fourth outputterminals that is configured to couple the second component of thephantom mode control signal onto the third and fourth differential pairsof conductive paths.

According to further embodiments of the present invention, methods ofoperating a network switch are provided in which a plug insertiondetection circuit may be used to automatically detect that a first enddevice is connected to a first end of a first channel that runs througha first of the connector ports of the network switch. A phantom modecontrol channel is used to determine a first identifier that isassociated with the first end device. A determination is made that thefirst end device is within a set of authorized end devices. In responseto this determination, the first of the connector ports is automaticallyenabled. In some embodiments, the method may further involve identifyinga service that is to be provided to the first end device based at leastin part on the first identifier, and then automatically reconfiguringthe network to provision the identified service to the first channel.

According to further embodiments of the present invention, methods ofautomatically identifying an end device that is connected to acommunications network are provided in which an interposer is mountedwithin a connector port on the end device. This interposer may include aplug end that mounts within the connector port on the end device and ajack end that is configured to receive a patch cord. A phantom modecontrol signal may be transmitted from the interposer to a connectorport on a patch panel of the communications network over a phantom modecontrol channel that runs from the interposer to the connector port onthe patch panel. The phantom mode control signal may be transmitted, forexample, in response to sensing that the patch cord has been pluggedinto the interposer. Alternatively or additionally, the phantom modecontrol signal may be transmitted in response to a control signal thatis transmitted over the control channel from the connector port on thepatch panel to the interposer. The phantom mode control signal mayinclude identifying information for the end device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating the contact arrangement for aconventional 8-position communications jack (TIA 568B) as viewed fromthe front opening (plug aperture) of the jack.

FIG. 2 is a simplified, schematic view of an exemplary cross-connectcommunications system on which the phantom mode signalling techniquesaccording to certain embodiments of the present invention may beimplemented.

FIG. 3 is a block diagram of a simplified cross-connect communicationspatching system according to embodiments of the present invention thatillustrates how common mode control signals may be used to trackpatching connections and end-to-end channel connectivity.

FIG. 4A is a schematic front view of a patch panel according toembodiments of the present invention that may be used as one of thepatch panels in FIG. 2 or 3.

FIG. 4B is an enlarged front view of a portion of a printed circuitboard of the patch panel of FIG. 4A.

FIG. 5A is a partial perspective view of a jack according to certainembodiments of the present invention.

FIG. 5B is a partial perspective view of a communications assembly thatis included in the jack of FIG. 5A.

FIG. 5C is a simplified, enlarged perspective view of a portion of thecommunications assembly of FIG. 5B.

FIGS. 6A-6B are views of alternative communications assemblies accordingto embodiments of the present invention that may be used in the jack ofFIG. 5A.

FIG. 7 is a schematic view of an inter-connect communications patchingsystem according to certain embodiments of the present invention.

FIG. 8A is a schematic perspective view of an interposer according toembodiments of the present invention.

FIG. 8B is a top view of a communications assembly of one of theconnectors of the interposer of FIG. 8A.

FIG. 8C is a side view of the communications assembly of FIG. 8B.

FIG. 8D is a schematic block diagram that illustrates phantom modecontrol signalling circuitry that may be included in the interposer ofFIGS. 8A-8C.

FIG. 9 is a simplified perspective view of a communications assembly ofa jack that includes a plug insertion/removal detection circuitaccording to certain embodiments of the present invention.

FIG. 10A is a schematic front view of part of a plug aperture of a jackthat includes a plug insertion/removal detection circuit according tofurther embodiments of the present invention that illustrates thepositions of the distal ends of the spring contacts when no plug isreceived within the plug aperture.

FIG. 10B is a schematic front view of the plug aperture of the jack ofFIG. 10A that illustrates the positions of the distal ends of the springcontacts when a plug is present within the plug aperture.

FIG. 10C is a block diagram illustrating how the phantom mode controlsignalling circuitry may be used to send an excitation signal to theplug insertion/removal detection circuit of FIGS. 10A-10B.

FIG. 11A is a schematic front view of the plug aperture of a jack thatincludes a plug insertion/removal detection circuit according to stillfurther embodiments of the present invention.

FIG. 11B is a schematic front view of the plug aperture of the jack ofFIG. 11A that illustrates the plug aperture when a plug is presentwithin the plug aperture.

FIG. 12 is a block diagram of the cable, connector ports, devices andcontrol elements associated with a portion of one exemplary channel inan interconnect communications patching system.

FIG. 13 is a flow chart diagram illustrating a method of automaticallyidentifying an end device that is connected to a communications networkaccording to certain embodiments of the present invention.

FIG. 14 is a flow chart that illustrates a method of operating a networkswitch according to certain embodiments of the present invention.

FIG. 15 is a flow chart that illustrates a method of identifyingconnectivity in a communications network according to certainembodiments of the present invention.

FIG. 16 is a block diagram illustrating the different types of lowvoltage cabling that may be wired to typical rooms in a commercialoffice building.

FIG. 17 illustrates how consolidator/encoder units and phantom modecontrol signalling techniques according to embodiments of the presentinvention may be used to reduce the amount of low voltage cablingrequired in certain commercial office buildings.

FIG. 18 is a flow chart diagram illustrating methods of detecting theinsertion and/or removal of a plug from a communications connectoraccording to embodiments of the present invention.

FIG. 19 is a flow chart diagram illustrating methods of detecting theinsertion and/or removal of a plug from a communications connectoraccording to further embodiments of the present invention.

FIG. 20 is a flow chart diagram illustrating methods of detecting theinsertion and/or removal of a plug from a communications connectoraccording to still further embodiments of the present invention.

FIG. 21A is a schematic front view of a jack that includes a pluginsertion/removal detection circuit according to further embodiments ofthe present invention.

FIG. 21B is a top schematic view of two electrodes that form a capacitorthat is part of the plug insertion/removal detection circuit of the jackof FIG. 21A.

FIG. 22A is a schematic front view of a jack that includes a pluginsertion/removal detection circuit according to still furtherembodiments of the present invention.

FIG. 22B is a top schematic view of a capacitor that is part of the pluginsertion/removal detection circuit of the jack of FIG. 22A.

FIG. 23A is a schematic block diagram of an interposer according tofurther embodiments of the present invention.

FIG. 23B is a schematic diagram illustrating the electrical connectionsfor one of the patch cords that is connected to a network device usingthe interposer of FIG. 23A.

DETAILED DESCRIPTION

Pursuant to embodiments of the present invention, methods and systems(and related connectors and equipment) for tracking connectivity in acommunications system are provided that use phantom mode controlsignals. These methods and systems may be used to track patchingconnections between two patch panel fields (i.e., in cross-connectpatching systems) or between a patch panel field and a plurality ofnetwork switches (i.e., in inter-connect patching systems).Additionally, in some embodiments, the methods and systems may be usedto track connections all the way to individual modular wall jacks and/orto end devices in the work area and/or in the computer room. Thus, thecommunications systems according to certain embodiments of the presentinvention can automatically (1) track patching connections between patchpanels and/or between patch panels and network switches, (2) monitorconnectivity of horizontal cabling to work area outlets and (3) trackend devices in order to determine the end-to-end connectivity of achannel. The methods and systems disclosed herein may be implemented onboth unshielded and shielded twisted pair communications systems.

In some embodiments, the phantom mode control signals that are used totrack connectivity may be inserted into a communications channel bycapacitively coupling the phantom mode control signal onto various ofthe conductors of the channel at one of the connector ports along thechannel. Such capacitive coupling techniques may be implemented at verylow cost within the connector ports, and may not require any changes tothe communications cables (including patch cords) that are used in thecommunications system. This is in stark contrast to many other existingand proposed intelligent patching solutions, which often requirespecialized patch cords that include extra conductors and modified plugconnectors. In some embodiments, the phantom mode control signaling maybe combined with technology that detects plug insertions and removalsat, for example, some or all of the connector ports in thecommunications system. Such plug insertion and removal detectiontechnology may provide a number of additional advantages, which will bediscussed below.

FIG. 2 is a schematic view of a cross-connect communications system 10that may be used to connect computers, printers, Internet telephones andother end devices that are located in work areas throughout a buildingto network equipment that is located, for example, in a computer room ofthe building. The phantom mode control signalling techniques discussedherein may be implemented on some or all of the channels of thecommunications system 10 of FIG. 2. As shown in FIG. 2, an exemplarycomputer 20 or other end device is located in a work area 12 of thebuilding. The computer 20 is connected by a patch cord 22 to a modularwall jack 24 that is mounted in a wall plate 26 in work area 12. Acommunications cable 28 is routed from the back end of the wall jack 24through, for example, the walls and/or ceiling of the building, to acomputer room 14. As there may be hundreds or thousands of work areawall jacks 24 in an office building, a large number of cables 28 may berouted into the computer room 14. While only a single work area enddevice (computer 20) is shown in FIG. 2 to simplify the drawing, it willbe appreciated that there would be dozens, hundreds or thousands of workarea end devices in a typical communications system.

A first equipment rack 30 is provided in the computer room 14. Aplurality of patch panels 32 are mounted on the first equipment rack 30.Each patch panel 32 includes a plurality of connector ports 34. Eachcable 28 from the wall jacks 24 in the work area 12 is terminated ontothe back end of one of the connector ports 34 of one of the patch panels32. In FIG. 2, each connector port 34 comprises an RJ-45 jack. However,it will be appreciated that other types of connector ports may be usedsuch as, for example, RJ-11 connector ports.

A rack controller 36 may also be mounted on the first equipment rack 30.The rack controller 36 may include a central processing unit (“CPU”) 38and a display 39. The rack controller 36 may be interconnected with rackcontrollers that are provided on other patch panel equipment racks ofthe communications system (only two such rack controllers 36 are shownin the example of FIG. 2) so that the rack controllers 36 cancommunicate in a common network as if they were a single controller. TheCPU 38 of rack controller 36 may include a remote access port thatenables the CPU 38 to be accessed by a remote computer such as, forexample, a system administrator computer (not shown in FIG. 2). The rackcontroller 36 may, for example, gather data from intelligent trackingcapabilities of the patch panels 32, as will be explained herein.

The communications patching system 10 further includes a second set ofpatch panels 32′ that are mounted on a second equipment rack 30′. Eachpatch panel 32′ includes a plurality of connector ports 34′, and a rackcontroller 36 may also be mounted on the second equipment rack 30′. Afirst set of patch cords 50 is used to interconnect the connector ports34 on the patch panels 32 to respective ones of connector ports 34′ onthe patch panels 32′.

As is further shown in FIG. 2, network devices such as, for example, oneor more network switches 42 and network routers and/or servers 46 aremounted, for example, on a third equipment rack 40. Each of the switches42 may include a plurality of connector ports 44, and each networkrouter and/or server 46 may also include one or more connector ports.One or more external communications lines 52 are connected to at leastsome of the network devices 46 (either directly or through a patch panelthat is not shown in FIG. 2). A second set of single-ended patch cords70 connects the connector ports 44 on the switches 42 to respective onesof the back ends of the connector ports 34′ on the patch panels 32′. Athird set of patch cords 54 may be used to interconnect other of theconnector ports 44 on the switches 42 with the connector ports providedon the network routers/servers 46. In order to simplify FIG. 2, only twopatch cords 50, a single patch cord 70 and a single patch cord 54 areshown.

The communications patching system of FIG. 2 may be used to connect eachwork area computer 20 or other work area end device to the networkswitches 42, the network switches 42 to the network routers and servers46, and the network routers/servers 46 to external communications lines52, thereby establishing the physical connectivity required to givedevices 20 access to both local and wide area networks. In thecross-connect patching system of FIG. 2, connectivity changes aretypically made by rearranging the patch cords 50 that interconnect theconnector ports 34 on the patch panels 32 with respective of theconnector ports 34′ on the patch panels 32′. It should also be notedthat in many cases the patching connections may be between patch panelsthat are mounted on the same equipment rack or even between connectorports on the same patch panel. Thus, it will be understood that FIG. 2illustrates the work area outlets being connected to patch panels thatare on a first equipment rack and the network switches being connectedto patch panels on a second equipment rack to provide a simple, easy tounderstand example. The present invention is not limited to suchconfigurations.

FIG. 2 illustrates one exemplary, rather simple, communications system10. It will be appreciated that many changes may be made to thecommunication system 10 without departing from the scope of the presentinvention. For example, the techniques disclosed herein can be employedon communications systems that are simpler than the exemplarycommunications system of FIG. 2. In other embodiments, the end-to-endconnectivity between work area end devices and network end devices maybe more complicated than shown in FIG. 2, with additional interveningpatch panels, consolidation points, horizontal cables, patch cords, etc.As will be discussed in more detail below, phantom mode control signalsmay be used to automatically determine and/or confirm patchingconnections between the patch panels 32 mounted on the first equipmentrack 30 and the patch panels 32′ mounted on the second equipment rack30′, thereby allowing a network administrator to automatically generateand subsequently maintain the computer-based log of patchingconnections. Additionally, in some embodiments, the communicationssystem 10 may also automatically track connections to the modular walljacks 24 and/or end-to-end device connectivity, as will be explained infurther detail below.

FIG. 3 is a block diagram illustrating a simplified communicationspatching system 100 that will be used to describe how phantom modecontrol signals may be used to track patch cord and/or cablingconnections in communications systems according to certain embodimentsof the present invention. Note that herein the terms “phantom modecontrol signal” and “phantom mode communications signal” are usedinterchangeably, and refer to a signal that is transmitted using phantommode signalling techniques that includes control information thereinsuch as, for example, information that may be used to track cablingconnections. It will be appreciated that the phantom mode controlsignals may also carry data in some embodiments.

As shown in FIG. 3, the communications patching system 100 includes afirst patch panel 110, a second patch panel 120, a network switch 130, aplurality of work area modular wall jacks 140 and various work area enddevices 150, 160. Network end devices (not shown in FIG. 3) would alsobe provided that are connected through the network switch 130. Patchcords 142 are used to interconnect connector ports 111-114 on the firstpatch panel 110 with connector ports 121-124 on the second patch panel120. The back ends of the connector ports 111-114 on the first patchpanel 110 are connected to the wall jacks 140 by respective horizontalcables 144. Patch cords 146 are used to connect the wall jacks 140 tothe respective connector ports 151, 161 on the end devices 150, 160. Theback ends of the connector ports 121-124 on the second patch panel 120are connected to respective connector ports 131-134 on the switch 130 byrespective single-ended patch cords 148. It will be noted that the blockdiagram of FIG. 3 shows a very simple communications patching systemwith two four-connector port patch panels 110, 120 and a single networkswitch 130 for purposes of illustrating operation of embodiments of thepresent invention, and it will be appreciated that typicalcommunications patching systems in which the present invention will beemployed will be much larger and far more complex than the exemplarysystem shown in FIG. 3.

As shown in FIG. 3, a phantom mode transmitter 115, a processor 116 anda phantom mode receiver 117 are provided on the first patch panel 110,and a phantom mode transmitter 125, a processor 126 and a phantom modereceiver 127 are provided on the second patch panel 120. A switch,multiplexer or the like (not shown in FIG. 3) may also be provided oneach of the first and second patch panels 110, 120 so that the phantommode transmitters 115, 125 and phantom mode receivers 117, 127 may beused to send/receive signals from each of the connector ports 111-114,121-124 on the respective patch panels 110, 120. In other embodiments,each connector port 111-114, 121-124 may have its own phantom modetransmitter and/or phantom mode receiver, and the switch or multiplexermay be omitted. Herein, the phantom mode transmitters, phantom modereceivers, processors and any associated switches or multiplexers thatare used to generate, receive and/or distribute phantom mode controlsignals are referred to generically as “phantom mode control signallingcircuitry.”

As is also shown in FIG. 3, in some embodiments, a phantom modetransmitter 135, a processor 136 and a phantom mode receiver 137 mayalso be provided on or at the network switch 130, although thesecomponents may be omitted in other embodiments. A switch or multiplexer(not shown in FIG. 3) may likewise be provided on network switch 130 sothat the phantom mode transmitter 135 and/or the phantom mode receiver137 may be shared across all of the connector ports 131-134 on networkswitch 130. As is further shown in FIG. 3, the work area end device 150may (optionally) include a phantom mode transmitter 152, a processor 154and/or a phantom mode receiver 156. Other work area devices such as thedepicted work area devices 160 may not include any phantom mode controlsignalling circuitry.

Operation of the phantom mode control channel will now be described withreference to FIG. 3. Operations may begin with the processor 116 on thefirst patch panel 110 sending a control signal to the phantom modetransmitter 115. In response to this control signal, the phantom modetransmitter 115 may generate and transmit a first phantom mode controlsignal 170 over a first phantom mode communications path that extendsfrom the first connector port 111 on the first patch panel 110 to thefirst connector port 121 on the second patch panel 120. As discussedabove, this first phantom mode communications path may comprise two ofthe differential pairs of the patch cord 142 that extends betweenconnector port 111 and connector port 121, and the phantom mode controlsignal 170 may be carried over this first phantom mode communicationspath simultaneously with differential communications signals that aretransmitted over the two differential pairs. (As will be discussedbelow, in other embodiments the phantom mode communications path may usemore than two of the differential pairs of the patch cord 142.) Thephantom mode control signal 170 may include, among other things, aunique identifier that is associated with the connector port 111. Forexample, in some embodiments, the unique identifier could be the serialnumber or MAC ID of the first patch panel 110 combined with a portnumber that identifies the connector port 111.

The first phantom mode control signal 170 is received at the connectorport 121 on the second patch panel 120, and then is extracted from theconnector port 121 in an appropriate manner (exemplary methods ofextracting phantom mode control signals from a phantom modecommunications path will be described later herein). The first phantommode control signal 170 is then routed to the phantom mode receiver 127on the second patch panel 120 (e.g., via a switch or multiplexer) wherethe signal is received and demodulated (if necessary). Thereceived/demodulated version of the first phantom mode control signal170 is then provided to the processor 126 on the second patch panel 120.As the processor 126 is able to determine that the received firstphantom mode control signal 170 was routed through connector port 121,the processor 126 may use the first phantom mode control signal 170 todiscover and/or confirm that a patch cord connection exists between thefirst connector port 111 on the first patch panel 110 (since the uniqueidentifier for this connector port is contained in the first phantommode control signal 170) and the first connector port 121 on the secondpatch panel 120. The processor 126 may provide this information to, forexample, a rack manager (e.g., rack manager 36 of FIG. 2), a systemmanager (not shown) and/or other processing devices that create and/ormaintain a log of the patch cord and cabling connections in thecommunications patching system 100.

In a similar fashion, the processor 126 on the second patch panel 120may send a control signal to the phantom mode transmitter 125 on thesecond patch panel 120. In response to this control signal, the phantommode transmitter 125 may generate a second phantom mode control signal171 and transmit this second phantom mode control signal 171 over thefirst phantom mode communications path that extends between the firstconnector port 111 on the first patch panel 110 and the first connectorport 121 on the second patch panel 120. The second phantom mode controlsignal 171 may include a unique identifier that is associated with theconnector port 121.

The second phantom mode control signal 171 is received at the connectorport 111 on the first patch panel 110, and then is extracted from theconnector port 111 in an appropriate manner. The second phantom modecontrol signal 171 may then be routed to the phantom mode receiver 117on the first patch panel 110, where the phantom mode control signal 171is received and demodulated (if necessary). The received/demodulatedversion of the second phantom mode control signal 171 is then providedto the processor 116 on the first patch panel 110. As the processor 116is able to determine that the received second phantom mode controlsignal 171 was routed through connector port 111, the processor 116 mayuse the second phantom mode control signal 171 to discover and/orconfirm that a patch cord connection exists between the first connectorport 111 on the first patch panel 110 and the first connector port 121on the second patch panel 120 (based on the unique identifier for thefirst connector port 121 on the second patch panel 120 that is includedin the second phantom mode control signal 171) The processor 116 mayprovide this information to, for example, a rack manager (e.g., rackmanager 36 of FIG. 2), a system manager (not shown) and/or otherprocessing devices that create and/or maintain a log of the patch cordand cabling connections in the communications patching system 100. Bysending phantom mode control signals over each connector port includedon the patch panels 110, 120, the processors 116, 126 can determine theconnections between the patch panels 110 and 120.

In the above description of the operation of the automatic connectiontracking capabilities of communications patching system 100, both thefirst patch panel 110 and the second patch panel 120 transmit phantommode control signals that are used to discover and/or confirm thepatching connections therebetween. However, it will be appreciated thatin other embodiments the number of phantom mode control signals may bereduced or changed. By way of example, in some embodiments, only thefirst patch panel 110 (or, in a more complex system, each of the patchpanels in the work area side patching field) will send phantom modecontrol signals to the second patch panel 120, as this may be sufficientto discover and provide to a connection database all of the patchingconnections between the first patch panel 110 and the second patch panel120. As another example, the system may alternatively be designed sothat only the second patch panel 120 (or, in the more complex systemmentioned above, each of the patch panels in the network side patchingfield) sends phantom mode control signals to the first patch panel 110.Other configurations are also obviously possible. Thus, it will beappreciated that the description herein simply provides examples as tohow the phantom mode control signalling techniques according toembodiments of the present invention may be used to automatically trackpatching connections, and that these examples are not intended to beexhaustive or limiting.

While changes in connectivity will typically be implemented in thecommunications system 100 by rearranging the connections formed by thepatch cords 142 between the connector ports 111-114 and 121-124 on thefirst and second patch panels 110, 120, connection changes may occur inother locations. By way of example, network switches such as switch 130typically include RJ-45 connector ports, and hence patch cords 148 areused to connect the connector ports 121-124 on the second patch panel tothe respective connector ports 131-134 on the switch 130 (these patchcords 148 typically are one-sided patch cords that each have a first endthat is directly terminated into the IDC array of one of the connectorports 121-124 of the second patch panel 120, and a second end thatincludes an RJ-45 plug that is plugged into one of the RJ-45 connectorports 131-134 on switch 130). The inclusion of patch cord connections atthe connector ports 131-134 of switch 130 leaves the possibility thatsomeone may intentionally or inadvertently rearrange the patchingconnections into the switch 130, and hence it may be desirable toautomatically track the patching connections between the patch panels inthe cross-connect field (e.g., patch panel 120 in the simplified exampleof FIG. 3) and the switch 130.

This tracking may be performed, for example, by having the processor 126on the second patch panel 120 send a control signal to the phantom modetransmitter 125 that causes the phantom mode transmitter 125 to generateand transmit a third phantom mode control signal 172 over a secondphantom mode communications path that extends from, for example, thefirst connector port 121 on the second patch panel 120 to the firstconnector port 131 on the switch 130. The second phantom modecommunications path may comprise two of the differential pairs of thepatch cord 148 that extends between connector port 121 and connectorport 131. The third phantom mode control signal 172 may include a uniqueidentifier that is associated with the connector port 121. For example,in some embodiments, the unique identifier could be the serial number orMAC ID of the second patch panel 120 combined with a port number thatidentifies the first connector port 121.

The third phantom mode control signal 172 is received at the connectorport 131 on the switch 130, and then is extracted from the connectorport 131 and routed to the phantom mode receiver 137 on the switch 130,where it is received and demodulated (if necessary). Thereceived/demodulated version of the third phantom mode control signal172 is then provided to the processor 136 on the switch 130. As theprocessor 136 is able to determine that the received signal was routedthrough the connector port 131, the processor 136 may use the thirdphantom mode control signal 172 to discover and/or confirm that a patchcord connection exists between the first connector port 121 on thesecond patch panel 120 and the first connector port 131 on the switch130. The processor 136 may provide this information to, for example, arack manager (not shown), a system manager (not shown) and/or otherprocessing devices that create and/or maintain a log of the patch cordand cabling connections in the communications patching system 100.

The processor 136 on the switch 130 may also (or alternatively) send acontrol signal to the phantom mode transmitter 135 that causes thephantom mode transmitter 135 to generate and transmit a fourth phantommode control signal 173 over the second phantom mode communications paththat extends between the first connector port 121 on the second patchpanel 120 and the first connector port 131 on the switch 130. Thisfourth phantom mode control signal 173 may include a unique identifierthat is associated with the connector port 131 (e.g., the serial numberor MAC ID of the switch 130 combined with a port number that identifiesthe first connector port 131). The fourth phantom mode control signal173 is received at, and extracted from, the connector port 121 on thesecond patch panel 120, and is then routed to the phantom mode receiver127 on the second patch panel 120, where it is received and demodulated(if necessary). The received/demodulated version of the fourth phantommode control signal 173 is then provided to the processor 126 on thesecond patch panel 120, thereby allowing the processor 126 to discoverand/or confirm that a patch cord connection exists between the firstconnector port 121 on the second patch panel 120 and the first connectorport 131 on the switch 130. The processor 126 may provide thisinformation to, for example, a rack manager (e.g., rack manager 36 ofFIG. 2), a system manager (not shown) and/or other processing devicesthat create and/or maintain a log of the patch cord and cablingconnections in the communications patching system 100.

It will be appreciated that while the above discussion envisions sendingphantom mode control signals in both directions between the second patchpanel 120 and the switch 130, in other embodiments the phantom modecontrol signals might only be sent in one direction. Thus, it will beappreciated that, in other embodiments, some of the hardware depicted inFIG. 3 may be omitted without degrading the capabilities of the system.As one example, the phantom mode receiver 137 on switch 130 (and perhapsthe phantom mode transmitter 125 on the second patch panel 120) may beomitted and the connections between the second patch panel 120 and theswitch 130 may be discovered solely by transmitting phantom mode controlsignals such as signal 173 from the switch 130 to the second patch panel120.

As is further shown in FIG. 3, at least some of the wall jacks 140 mayinclude a phantom mode transmitter 142, a processor 144 and/or a phantommode receiver 146. The provision of phantom mode signalling capabilitiesat the wall jacks 140 may allow the automatic discovery and/orconfirmation of the connections of the horizontal cables 144 thatconnect the wall jacks 140 (or other work area outlets) to the patchpanels in the work area patch panel field (e.g., patch panel 110) in thecomputer room, and various other capabilities may also be provided oversuch a phantom mode control channel (e.g., the ability for a systemadministrator to determine from a remote location whether or not a patchcord is plugged into one of the wall jacks 140).

A horizontal cabling connection such as the connection between connectorport 112 on the first patch panel 110 and wall jack 140 may be trackedas follows. First, the processor 116 on the first patch panel 110 sendsa control signal to the phantom mode transmitter 115 that causes thephantom mode transmitter 115 to generate and transmit a fifth phantommode control signal 174 over a third phantom mode communications paththat extends from the connector port 112 on the first patch panel 110 tothe wall jack 140. The third phantom mode communications path maycomprise two of the differential pairs of the horizontal cable 144 thatextends between connector port 112 and wall jack 140.

The fifth phantom mode control signal 174 is received at the wall jack140, and then is extracted from the channel and routed to the phantommode receiver 146, where it is received and demodulated (if necessary).The received/demodulated version of the fifth phantom mode controlsignal 174 is then provided to the processor 144. The fifth phantom modecontrol signal 174 prompts the processor 144 to send a control signal tothe phantom mode transmitter 142 that causes the phantom modetransmitter 142 to generate and transmit a sixth phantom mode controlsignal 175 over the third phantom mode communications path that extendsbetween the wall jack 140 the connector port 112. This sixth phantommode control signal 175 may include a unique identifier that isassociated with the wall jack 140 (e.g., an office number where the walljack is located and the port number of the wall jack). The sixth phantommode control signal 175 is received at, and extracted from, theconnector port 112 on the first patch panel 110, and is then routed tothe phantom mode receiver 117 on the first patch panel 110, where it isreceived and demodulated (if necessary). The received/demodulatedversion of the sixth phantom mode control signal 175 is then provided tothe processor 116 on the first patch panel 110, thereby allowing theprocessor 116 to discover and/or confirm the horizontal cablingconnection between connector port 112 and wall jack 140. The processor116 may provide this information to, for example, a rack manager (e.g.,rack manager 36 of FIG. 2) or a system manager (not shown).

The horizontal cables 144 that extend between the work area wall jacks140 and the work area patch panel field (i.e., patch panel 110 in thesimplified example of FIG. 3) are typically directly terminated intoback end wire connection assemblies of the connector ports 111-114 onthe first patch panel 110 and on the wall jacks 140, and hence cannotreadily be removed and connected to other connector ports or jacks.Consequently, the horizontal cables 144 typically are not rearranged,and hence once a communications network has been installed, there maynot be a compelling need to automatically track the connections betweenthe first patch panel 110 and the wall jacks 140 that is sufficient tojustify the added expense of providing phantom mode signallingcapabilities at each wall jack 140. However, if phantom mode signallingcapabilities are provided at the wall jacks 140, they may be used for avariety of purposes such as, for example, confirming that all of thehorizontal cables were properly connected during the installation of thenetwork and/or for detecting patch cord insertions and/or removals usingvarious techniques that are described below.

Most intelligent communications patching systems do not have thecapability to track connections to work area end devices such as the enddevices 150, 160 of FIG. 3. However, according to some embodiments ofthe present invention, phantom mode control channels may be providedthat extend all the way to work area end devices which may be used toautomatically identify the work area end devices that are connected to acommunications network. While not shown in FIG. 3, phantom mode controlchannels may also be provided that extend to network end devices such asnetwork servers, memory storage devices, etc. These phantom mode controlchannels may be used to track the actual end devices that are connectedto the communications system 100. This may be advantageous for a varietyof reasons, as it allows a system administrator to discover the fullend-to-end connectivity of the devices that are communicating over thecommunications system 100. This information may be used to, for example,provide enhanced security, automatically provision services to certainend devices, confirm that redundancy requirements and other networkrules are being followed, and prohibit unauthorized access to thenetwork, as will be discussed in greater detail below.

The capability of communications systems according to embodiments of thepresent invention to discover and track end devices will now bedescribed with respect to the work area end device 150 of FIG. 3. Asshown in FIG. 3, the processor 116 on the first patch panel 110 may senda control signal to the phantom mode transmitter 115 that causes thephantom mode transmitter 115 to generate and transmit a seventh phantommode control signal 176 over a fourth phantom mode communications paththat extends from the first connector port 111 on the first patch panel110, through a wall jack 140, to a connector port 151 that is providedon the end device 150. The fourth phantom mode communications path maycomprise, for example, two of the differential pairs on the horizontalcable 144 that extends between connector port 111 and wall jack 140, thecorresponding two differential pairs in the wall jack 140, and thecorresponding two differential pairs on the patch cord 146 that extendsbetween wall jack 140 and connector port 151. The seventh phantom modecontrol signal 176 is received at the connector port 151 on the enddevice 150, and then is extracted from the connector port 151 and routedto the phantom mode receiver 156, where it is received and demodulated(if necessary). The received version of the seventh phantom mode controlsignal 176 is provided to the processor 154 on the work area end device150, and is used to prompt the processor 154 to cause the phantom modetransmitter 152 to send an eighth phantom mode control signal 177 backto the first patch panel 110 over the fourth phantom mode communicationspath. This eighth phantom mode control signal 177 may include a uniqueidentifier that is associated with the end device 150 such as, forexample, the MAC ID of the device. The eighth phantom mode controlsignal 177 is received at, and extracted from, the connector port 111 onthe first patch panel 110, and is then routed to the phantom modereceiver 117 on the first patch panel 110, where it is received anddemodulated (if necessary). The received/demodulated version of theeighth phantom mode control signal 177 is then provided to the processor116 on the first patch panel 110, thereby allowing the processor 116 todiscover which particular work area end device 150 is connected throughconnector port 111. The processor 116 may provide this information to,for example, a rack manager (e.g., rack manager 36 of FIG. 2), a systemmanager (not shown) and/or other processing devices that create and/ormaintain a log of the patch cord and cabling connections in thecommunications patching system 100. It will be appreciated that in someembodiments, the control signal 176 may be omitted, and the processor154 on work area device may instead simply periodically (ornon-periodically) transmit the eighth phantom mode control signal 177without prompting.

Thus, in the exemplary manner described above, phantom mode controlsignals may be used to discover and/or confirm patching connections inthe communications patching system 100, and/or to discover whichspecific end devices are connected on each channel.

While the discussion above regarding operation of the communicationssystem of FIG. 3 discusses having modulated signals that include a datastream therein, it will be appreciated that the present invention is notso limited. For example, in other embodiments, the presence of a carrieror a phantom mode control signal can be used in of itself to, forexample, confirm a patching connection.

It will be appreciated that once a phantom mode control signal isinjected onto one or more of the differential pairs of a particularchannel, that phantom mode control signal may propagate all the way fromone end of the channel to the other end of the channel through multiplecable segments and connectors. By way of example, in the communicationspatching system of FIG. 3, the eighth phantom mode control signal 177will propagate all the way from the end device 150 to the connector port131 on the network switch 130 over the channel extending therebetween.Moreover, as shown in FIG. 3, more than one device can inject phantommode control signals onto a particular channel. For example, in thecommunications patching system 100 of FIG. 3, the end device 150, thefirst patch panel 110, the second patch 120, and the switch 130 (andeven the wall jacks 140 in some embodiments) can inject phantom modecontrol signals onto the channel extending, for example, betweenconnector port 151 on end device 150 and connector port 131 on switch130. Consequently, techniques may be used that prevent the multiplephantom mode control signals that may be transmitted on a particularchannel from interfering with each other, and/or which allow the devicesin the communications system 100 to distinguish between these differentphantom mode control signals. For example, in one such embodiment, eachdevice on a particular channel may be assigned a particular time slot ina time division multiple access communication scheme that allows thedevices on a particular channel to send phantom mode control signalswithout interference and which allows each device to distinguish betweenthe different phantom mode control signals. In other embodiments,frequency division multiple access schemes may be used. In still otherembodiments, arbitration procedures may be used that prevent thetransmission of interfering signals, and identification information maybe included in the phantom mode control signals that allow the devicesthat receive such signals to determine the source of the signal. Otherprocedures and techniques may also be used.

A variety of different phantom mode control signals may be used. Forexample, the phantom mode control signal may or may not be modulatedonto a carrier frequency. In one particular embodiment, the phantom modecontrol signal may comprise a frequency shift keyed (“FSK”) alternatingcurrent signal that is modulated onto, for example, a 50 MHz carriersignal. In other embodiments, higher, out-of-band frequencies may beused (e.g., 800 MHz) to reduce the possibility that the phantom modecontrol signals interfere with the differential information signals thatare also carried on the conductors of the phantom mode communicationspath. It will also be appreciated that other carrier frequencies and/ormodulation types may be used. Modulated signals may be preferred in someembodiments because the magnitude of the phantom mode control signal maybe reduced significantly (e.g., by 70 dB) through the capacitivecoupling techniques that may be used to both inject the phantom modecontrol signal into a channel and to extract the phantom mode controlsignal from the channel in certain embodiments of the present invention.Such modulated signals may be less susceptible to corruption by noise.The magnitude of the phantom mode control signal may be set at a varietyof levels. In some embodiments, the magnitude may be between about 0.5volts and 3 volts, although a wide variety of magnitudes may be used. Intypical implementations the phantom mode control signal is analternating current signal, as such a signal will not be blocked bycoupling capacitors and is compatible with Power-over-Ethernet patchingsystems.

It has further been discovered that in some embodiments the use ofphantom mode control signals having a carrier frequency of between 25MHz and 100 MHz may be preferred in certain situations. In particular,if higher frequency phantom mode control signals are used, excessivemode conversion may occur where a portion of the phantom mode controlsignal is converted to a differential mode signal that can potentiallyinterfere with an information signal being transmitted differentially ona pair of conductors in the channel due to, for example, an imbalance inthe transmission lines. This mode conversion can deleteriously impactchannel performance, and can also lead to alien crosstalk problems onother channels in cabling that is bundled with the cables that carry thephantom mode control signal. Such mode conversion problems may bereduced for phantom mode control signals in the 25 MHz to 100 MHz range.Additionally, while even higher frequencies may be used such as, forexample, frequencies greater than 800 MHz or 1 GHz that may fall outsideof the band of the information signals carried on the differentialpairs, the transmission losses over copper conductors may beprohibitively high at these frequencies, particularly where long cablingruns are used as may be commonplace in data centers and large commercialoffice buildings.

FIGS. 4A-4B illustrate a patch panel 200 that may be used, for example,as one of the patch panels 32, 32′ of FIG. 2 or as one of the patchpanels 110, 120 of FIG. 3. FIG. 4A is a front view of the patch panel200, while FIG. 4B is a schematic front view of a portion of a printedcircuit board 230 of patch panel 200.

As shown in FIG. 4A, the exemplary patch panel 200 includes a mountingframe 210 and twenty-four connector ports 220 that are, in thisembodiment, arranged as four groups of six connector ports 220. Eachconnector port 220 is implemented as an RJ-45 jack. A printed circuitboard 230 is mounted on the front face of the mounting frame 210 andincludes cut-out areas for each of the connector ports 220. The printedcircuit board 230 is shown in outline representation in FIG. 4A as itmay be partly or completely hidden beneath a cover or other protectiveor aesthetic housing. Trace buttons 240 and light emitting diodes(“LED”) 250 may be mounted on the printed circuit board 230 adjacenteach of the connector ports 220. The trace buttons 240 and LEDs 250 maybe electrically connected to a microprocessor 280 (see FIG. 4B), and maybe used, for example, to perform line tracing functions. In someembodiments, the trace buttons 240 and/or the LEDs 250 may be omitted.As is also shown in FIG. 3, the patch panel 200 further includes aconnection 260 that receives one end of a communications cable 270(e.g., a ribbon cable, an RJ-45 patch cord, etc.). The other end of thecommunications cable 270 may be connected directly or indirectly to, forexample, a rack manager 36 (see FIG. 2). The connection 260 andcommunications cable 270 provide a communications path that allowsinformation to be communicated to and from the components that aremounted on the printed circuit board 230 of patch panel 200 and the rackcontroller 36 (or other external processing device). A power connectionmay also be provided (not shown) that provides power to the patch panel200.

FIG. 4B is an enlarged schematic front view of a portion of the printedcircuit board 230 of the intelligent patch panel 200 of FIG. 4A. Theprinted circuit board 230 may be generally rectangular in shape, and ismounted on top of the connector ports 210 (which are accessible throughapertures in the printed circuit board 230 in the particular embodimentof FIGS. 4A-4B). The trace buttons 240 and the LEDs 250 are mounted onthe printed circuit board 230 and are positioned to be above arespective one of the connector ports 220. The patch panel 200 may alsoinclude a plug insertion/removal detection circuit for each of theconnector ports 220 (not shown in FIGS. 4A-4B). Exemplary embodiments ofsuch plug insertion/removal detection circuits will be described below.

As shown in FIG. 4B, a phantom mode transmitter 260, a phantom modereceiver 270, a microprocessor 280 and a multiplexer 290 may also bemounted on the printed circuit board 230. The printed circuit board 230may also include first and second contact pads 265 for each connectorport 220 that are mounted on a back side of printed circuit board 230(and hence are shown using dotted lines in FIG. 4B). Each pair ofcontact pads 265 is configured to mate with a pair of phantom modecontacts that are provided on each connector port 220 included on thepatch panel 200 (see FIG. 5A, which shows phantom mode contacts 366, 376that are implemented on a modular RJ-45 wall jack that may be used toimplement each connector port 220). As will be discussed in detailbelow, the phantom mode contacts may be used to couple phantom modecontrol signals to and from the connector ports 220 and the phantom modetransmitter 260 and/or the phantom mode receiver 270.

As shown in FIG. 4B, the microprocessor 280 includes an output that isconnected to the phantom mode transmitter 260. This output may be usedto send control signals to the phantom mode transmitter 260 that controloperation of the phantom mode transmitter 260. The microprocessor 280further includes an input (which may be a serial or parallel input) thatmay receive data that is extracted from phantom mode control signalsthat are received by the phantom mode receiver 270. The multiplexer 290is coupled to both the phantom mode transmitter 260 and the phantom modereceiver 270, and includes input/output lines (not shown in FIGS. 4A-4B)that are coupled to each pair of contact pads 265. The multiplexer 290may be used to pass a phantom mode control signal that is transmitted bythe phantom mode transmitter 260 to the pair of contact pads 265 thatare associated with a specific connector port 220. The multiplexer 290may also be used to pass a phantom mode control signal that is receivedat a specific one of the connector ports 220 by connecting the pair ofcontact pads 265 associated with that specific connector port 220 to thephantom mode receiver 270. The microprocessor 280 may be used to controlthe settings on the multiplexer 290. By providing the multiplexer 290,which is used to selectively connect the pair of contact pads 265associated with the various connector ports 220 to the phantom modetransmitter 260 and/or the phantom mode receiver 270, it may only benecessary to provide a single phantom mode transmitter 260 and phantommode receiver 270 per patch panel 200. This can substantially reduce thecost of the patch panel 200. The multiplexer 290 may comprise, forexample, an analog multiplexer (or a cascaded set of analogmultiplexers).

While in the particular embodiment depicted in FIG. 4B the multiplexer290 is used as a switching device that allows the phantom modetransmitter 260 and/or the phantom mode receiver 270 to be selectivelyconnected to the connector ports 220, it will be appreciated that anyappropriate switching device may be used. By way of example, theswitching circuits disclosed in co-pending U.S. patent application Ser.No. 11/871,448, filed Oct. 12, 2007, that are used to selectivelyconnect an RFID transceiver to the connector ports on a patch panelcould be used in place of the multiplexer 290 in alternative embodimentsof the present invention. The disclosure of U.S. patent application Ser.No. 11/871,448 is incorporated by reference here in its entirety.

While not shown in FIG. 4B to simplify the drawing, it will beappreciated that the microprocessor 280 may include control lines thatare used to send and receive control and/or power signals to the tracebuttons 240 and/or the LEDs 250. Individual control lines may beprovided for each trace button/LED, and or common control lines may beprovided that are selectively routed through a multiplexer or switchingcircuit.

While in the embodiment of FIGS. 4A-4B the phantom mode transmitter 260,the phantom mode receiver 270, the microprocessor 280 and themultiplexer 290 are mounted on the patch panel 200, it will beappreciated that some or all of these components may be mounted in otherplaces. As one example, some or all of these components could be mountedon the rack manager and the signals could be routed to and from thepatch panels on the rack via a bus or other means. Such animplementation could further reduce the number of active componentsrequired (although perhaps with a corresponding increase in the size ofthe multiplexer/switching circuits).

FIGS. 5A-5C illustrate a modular jack 300 according to certainembodiments of the present invention. In particular, FIG. 5A is aperspective view of the jack 300, FIG. 5B is a partial perspective viewof a communications assembly 320 that is included in the jack 300 ofFIG. 5A, and FIG. 5C is a simplified and enlarged perspective view of aportion of the communications assembly 320 of FIG. 5B. The modular jack300 may be used, for example, as the connector ports 34, 34′ that areincluded on patch panels 32, 32′ of FIG. 2, as the connector ports111-114, 121-124 on the patch panels 110, 120 of the communicationspatching system 100 of FIG. 3 (and also as the wall jacks 140), and/oras the connector ports 220 on the patch panel 200 of FIG. 4.

Turning first to FIG. 5A, it can be seen that the jack 300 includes anelectrically insulative or dielectric jack housing 312, terminal housing314 and cover 316. The parts 312, 314 and 316 may be collectivelyreferred to herein as the “connector housing.” The jack housing 312includes a plug aperture opening 313 that is sized and configured toreceive a modular plug (not shown in the figures) that is inserted intothe jack housing 312. The jack housing 312 receives a front part of thecommunications assembly 320, which is inserted into an opening in therear of the jack housing 312. The terminal housing 314 is fitted overand protects a first surface of the communications assembly 320. Cover316 fits beneath the communications assembly 320 and attaches to theterminal housing 314 to protect a second surface of the communicationsassembly 320 that is opposite the first surface.

As is further shown in FIG. 5A, the jack 300 also includes a pair ofphantom mode contacts 366, 376. Each of the phantom mode contacts 366,376 may comprise a conductive wire. A termination end of each of theseconductive wires may be mounted into the bottom surface of a printedcircuit board 330 (see FIGS. 5B and 5C) of the communications assembly320. The termination ends of the phantom mode contacts 366, 376 may eachhave, for example, an eye-of the needle configuration so that they maybe press fit into respective metal-plated apertures in the printedcircuit board 330. Those skilled in the art will appreciate, however,that as an alternative to the method illustrated in FIGS. 5A-5C, thetermination ends of the phantom mode contacts 366 may form springcontacts that are configured to contact respective pads, located on thebottom surface 334 of the printed circuit board 330, which are connectedby conductive traces to the posts 364 and 374. In some embodiments, thetermination ends of the phantom mode contacts 366, 376 may form therespective posts 364, 374 that are discussed below with respect to FIGS.5B and 5C. The conductive wires that form the respective phantom modecontacts 366, 376 make a 90-degree bend as they exit the printed circuitboard 330 so that they run along the bottom of the printed circuit board330 towards the front of the jack 300. At the front of the jack 300,each of the phantom mode contacts 366, 376 is bent downwardly to form ashallow “V” shape. The distal end of each of the phantom mode contacts366, 376 rests against a front part of the jack housing 312. As such,the V-shaped portion of each phantom mode contacts 366, 376 forms aspring contact that is configured to contact a respective one of thecontact pads 265 that are mounted on the reverse side of the patch panelprinted circuit board 230. Thus, the phantom mode contacts 366, 376provide electrical paths that may be used to transmit the two componentsof a phantom mode control signal between the patch panel printed circuitboard 230 and the printed circuit board 330 of the jack 300 when thejack 300 is used to form the connector ports 220 of patch panel 200.

Turning to FIGS. 5B-5C, it can be seen that the communications assembly320 includes a printed circuit board 330. The printed circuit board 330may comprise any conventional or non-conventional printed circuit orwiring board. In the depicted embodiment, the printed circuit board 330is a conventional printed circuit board that includes a multi-layereddielectric substrate that has a top surface 332, a bottom surface 334, aforward edge 336 and a rear edge (note that the printed circuit board330 is inverted in FIGS. 5B and 5C as compared to its orientation inFIG. 5A; for ease of description the discussion of FIGS. 5A-5C belowwill use words such as “top,” “bottom,” etc. to match the orientationshown in FIGS. 5B and 5C). A plurality of spring contacts 341-348 aremounted in cantilevered fashion to extend from the top surface 332 ofprinted circuit board 330. Each spring contact 341-348 may be mounted ina metal-plated hole in the top surface 332 of the printed circuit board330. Herein, the term “contact”, when used as a noun, refers to anelectrically conductive element that is designed to establish physicaland electrical contact with an external electrically conductive element.The contacts 341-348 are referred to as “spring” contacts because thecontacts 341-348 are configured to resiliently deflect from a restingposition when contacted by a mating plug, then spring back to theresting position when the plug is removed. The free ends of the springcontacts 341-348 terminate near the forward edge 336 of printed circuitboard 330, and may be offset vertically from the top surface 332 ofprinted circuit board when the spring contacts 341-348 are in theirnormal resting position (i.e., in the position that they assume when notengaged by a mating plug). The spring contacts 341-348 may be formed,for example, of a copper alloy such as spring-tempered phosphor bronze,beryllium copper, or the like. A typical cross-section of each springcontact 341-348 may be, for example, 0.015 inch wide by 0.010 inchthick, although other sized and/or shaped (e.g., round) contacts may beused.

The communications assembly 320 also includes a plurality of wireconnection terminals 368 (see FIG. 5A) that are likewise mounted intorespective ones of additional plurality of metal-plated holes in the topsurface 332 of printed circuit board 330. The wire connection terminals368 may be implemented, for example, as conventional insulationdisplacement contact terminals (IDCs). The IDCs 368 may include a basehaving a “needle-eye” construction that allows the base to be press-fitinto its respective metal-plated hole in the printed circuit board 330or, alternatively, may be soldered in place. While the IDCs 368 are notdepicted in FIGS. 5B-5C (and are barely visible in FIG. 5A as they arerecessed within the terminal housing 314) in order to simplify thedrawings, the IDCs may, for example, be identical to the IDCs 242, 244,246, 248 illustrated in U.S. Pat. No. 7,204,722, the contents of whichare incorporated herein by reference. The IDCs 368 may be positioned intwo rows located along the side edges of the printed circuit board 330,where each row extends from approximately the middle of the printedcircuit board 330 to the rear edge of the board 330 (i.e., in the sameconfiguration as the IDCs depicted in the above-mentioned U.S. Pat. No.7,204,722). As shown in FIG. 5A, the terminal housing 314 mounts overthe IDCs 368 to protect the IDCs 368 and the top surface 332 of theprinted circuit board 330. The terminal housing 314 also includes slotsthat allow the conductors of a communications cable to be inserted intothe respective IDCs 368.

The cover 316 may protect the bottom surface 334 of at least part of theprinted circuit board 330. The cover 316 may be permanently joined tothe terminal housing 314 (e.g., by ultrasonic welding) such that thecommunications assembly 320 is “sandwiched” or captured between theterminal housing 314 and the cover 316.

As also shown in FIG. 5A, the jack housing 312 has a latch 315protruding below its rear opening. The bottom forward edge of the cover316 includes a raised protrusion that mates with the latch 315. Theterminal housing 314 likewise has a pair of side catches 322 protrudingfrom the forward part of both sides of the housing 314 (only one sidecatch 322 is visible in FIG. 5A). The side catches 322 may comprise, forexample, snap clips that have hooked projecting ends that are configuredto snap into and lock within respective recesses provided in the sidewalls of the jack housing 312. The terminal housing 314 may be joined tothe cover 316 with the communications assembly 320 capturedtherebetween, and then the forward edge 336 of the communicationsassembly 320 may be inserted into the rear opening in the jack housing312 until the side catches 322 of terminal housing 314 snap into placein their respective recesses in the jack housing 312 and until the latch315 snaps over and onto the raised protrusion on the bottom of cover 316to securely join the jack housing 312 to the remainder of the jack 300.

The jack housing 312, the terminal housing 314 and the cover 316 may beformed, for example, of a plastic material that meets applicablestandards with respect to electrical insulation and flammability, suchas Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), orpolycarbonate. It will be appreciated that many other electricallyinsulative or dielectric materials may be used.

While the jack housing 312, the terminal housing 314 and the cover 316provide one example of a housing structure that may enclose thecommunications assembly 320, it will be appreciated that a wide varietyof different housing structures could be used, and/or that thecommunications assembly 320 may be constructed as part of the housingitself as opposed to as a separate piece or pieces. Thus, embodiments ofthe present invention need not be limited to any particular housingstructure, and the above-provided detailed description of one particularhousing structure is only provided so that the present disclosure willbe thorough and complete.

The printed circuit board 330 further includes a plurality of additionalelements. These elements may include a plurality of conductive traces orpaths 349 (shown partially in FIG. 5B) that extend between andelectrically connect the metal-plated holes that receive the springcontacts 341-348 to a respective one of the metal-plated holes thatreceive the IDCs 368. Each conductive trace/path 349 provides acommunications path that allows an information signal that is input on arespective one of the spring contacts 341-348 to be carried through thejack 300 and output onto a respective one of the IDCs 368, and viceversa. The conductive trace/paths 349 may simply comprise a copper tracethat resides on a single layer of the printed circuit board 330, oralternatively may comprise, for example, a series of conductive vias andconductive trace segments that reside on multiple layers of the printedcircuit board 330 that together electrically connect one of themetal-plated holes that receive the spring contacts 341-348 to arespective one of the metal-plated holes that receive the IDCs 368. Aplurality of crosstalk compensation circuits (e.g., element 333) andalien crosstalk compensation circuits (e.g., element 335) may also beprovided on or within the printed circuit board 330. For example,crosstalk compensation circuits such as those depicted in U.S. Pat. No.7,190,594 may be provided, and alien crosstalk compensation circuitssuch as those depicted in U.S. Pat. No. 7,179,115 may be provided. Theentire contents of the aforementioned U.S. Pat. Nos. 7,190,594 and7,179,115 are incorporated in their entireties herein by reference.

Turning again to FIGS. 5B-5C, it can be seen that a plurality of contactpads 351-358 are provided on the top surface 332 of the printed circuitboard 330 (and/or within the printed circuit board 330). Each of thecontact pads 351-358 is arranged so as to mate with the distal end of arespective one of the spring contacts 341-348 when a modular plug isinserted into plug aperture 313 of the jack 300. When the modular plugis inserted, the distal ends of each of the spring contacts 341-348 aredeflected downwardly so as to come into mechanical and electricalcontact with a respective one of the contact pads 351-358. In theparticular embodiment depicted in FIGS. 5A-5C, the middle four contactpads 353-356 are used to electrically connect the middle four contactwires 343-346 to crosstalk compensation capacitors 333 (see FIG. 5B)that are embedded within the printed circuit board 330 near the frontedge 336 thereof. The remaining four contact pads 351-352 and 357-358are used to capacitively couple a phantom mode control signal eitheronto, or off of, pairs 2 and 4 of the connector 300 (as discussed withrespect to FIG. 1 above, pairs 2 and 4 are the outside pairs of contactsin the TIA/EIA 568 type B contact configuration), as will be discussedin further detail below. The contact pads 351-358 may be implemented asany conductive pad or other structure that makes reliable electricalcontact with its respective one of the spring contacts 341-348 underappropriate conditions (e.g., when a plug is inserted into the jack).The contact pads 351-358 may comprise generally two-dimensional platedmetal pads or may comprise three-dimensional structures such as, forexample, conductive nails, blocks, columns or the like that extend abovethe top surface 332 of the printed circuit board 330.

The distal ends of the spring contacts 341-348 are normally not incontact with their respective contact pads 351-358. However, when amodular plug (not shown in the figures) is inserted into the plugaperture 313, blades or other contacts of the plug physically contactrespective ones of the spring contacts 341-348. The spring contacts341-348 are resiliently deflected by the plug blades downwardly towardthe top surface 332 of the printed circuit board 330, thereby bringingeach spring contact 341-348 into mechanical and electrical contact witha respective one of the contact pads 351-358.

When the spring contacts 341-348 mate with respective ones of thecontact pads 351-358, an electrical connection is established such thatan electrical signal may pass from each spring contact 341-348 to itsrespective contact pad 351-358 (or vice versa). The contact pads 351-358may be formed of a variety of conductive materials such as, for example,copper or copper alloys (with or without plating). In certainembodiments of the present invention, the contact pads 351-358 maycomprise a gold or nickel plated copper alloy. In the particularembodiment depicted in FIGS. 5A-5C, the contact pads 351-358 comprisegenerally rectangular pads that are deposited on the top surface 332 ofthe printed circuit board 330. While an insulative layer is typicallydeposited on top of the conductive traces 349 that are provided on thetop surface 332 or bottom surface 334 of a printed circuit board 330 inorder to, among other things, protect such traces 349 and/or to preventinadvertent short circuits, it will be appreciated that such aninsulative layer, if provided, is not present at the location of eachcontact pad 351-358. This allows each contact pad 351-358 to make anelectrical connection with a respective one of the spring contacts341-348 when a modular plug is inserted in the jack 300.

As shown in FIGS. 5B and 5C, first and second plates 360, 370 areembedded in interior layers of the printed circuit board 330. The firstplate 360 is positioned under the contact pads 351-352, and the secondplate 370 is positioned under the contact pads 357-358. Plate 360 iselectrically connected by a printed circuit board trace 362 to aconductive post 364. This conductive post 364 is electrically connectedto a phantom mode contact 366 (see FIG. 5A) which, as discussed above,mates with one of the contact pads 265 that are associated with the jack300 on the patch panel printed circuit board 230. Likewise, plate 370 iselectrically connected by a printed circuit board trace 372 to aconductive post 374. This conductive post 374 is electrically connectedto a phantom mode contact 376 (see FIG. 5A) which, as discussed above,mates with the other one of the contact pads 265 that are associatedwith the jack 300 on the patch panel printed circuit board 230. In someembodiments, the conductive posts 364, 374 may be replaced with, forexample, respective metal-plated vias, and the phantom mode contacts366, 376 may be mounted in the respective metal-plated vias to establishthe electrical connections between the phantom mode contacts 366, 376and the respective printed circuit board traces 362, 372.

The plate 360 and the contact pads 351 and 352 reside on differentlayers of the printed circuit board 330, and are thus separated by adielectric substrate form each other. These components together form afirst capacitor that may be used to capacitively couple a portion of aphantom mode control signal to and/or from one of the four differentialpairs of conductive paths that run through jack 300. In particular, theplate 360 forms a first capacitor electrode and the contact pads 351 and352 form respective second and third electrodes of the capacitor thatmay be used to connect to two of the conductive paths through the jack300. The capacitor formed by plate 360 and contact pads 351-352comprises a “three-terminal” capacitor as it capacitively couples energybetween three distinct electrical paths. The plate 370 and the contactpads 357-358 form a second three-terminal capacitor that may be used tocapacitively couple another portion of a phantom mode control signal toand/or from another one of the four differential pairs of conductivepaths that run through jack 300. The first capacitor formed by elements360, 351, 352, the second capacitor formed by elements 370, 357, 358 andthe corresponding electrical connections (e.g., traces 362, 372 andposts 364, 374 and phantom mode contacts 366, 376) together form acontrol signal input circuit that may be used to inject a control signalinto the channel that passes through jack 300. Note that theabove-described three-terminal capacitors may also be viewed as twoseparate standard capacitors (e.g., the first three-terminal capacitordescribed above may alternatively be viewed as a first capacitor thathas electrodes 360 and 351 and a second capacitor that has electrodes360 and 352).

A phantom mode control signal that is carried into the jack 300 on pairs2 and 4 of a patch cord that is plugged into jack 300 may be coupledfrom the channel that passes through the jack 300 as follows. For thepurposes of this example, it will be assumed that the positive componentof the phantom mode control signal is carried on pair 2 and the negativecomponent of the phantom mode control signal is carried on pair 4. Notethat since the phantom mode control signal may be an alternating currentsignal, in some cases the signal on each pair may oscillate betweenbeing a positive signal and a negative signal. Consequently, it will beappreciated that references herein to a “positive component” or a“negative component” of a phantom mode signal are used to refer to thecomponents of the phantom mode signal at a given point in time in orderto conveniently be able to distinguish between the two components of thedifferential phantom mode signal.

The positive component of the phantom mode control signal passes throughthe plug blades of pair 2 onto spring contacts 341-342, and the negativecomponent of the phantom mode control signal passes through the plugblades of pair 4 onto spring contacts 347-348. The plug blades press thespring contacts 341-348 downwardly so that the distal end of each springcontact 341-348 makes firm mechanical and electrical contact with itsrespective mating contact pad 351-358. Some of the signal energy of thepositive component of the phantom mode control signal that is present onspring contacts 341-342 and mating contact pads 351-352 willcapacitively couple from the contact pads 351-352 through the dielectricsubstrate of printed circuit board 330 to the plate 360. Likewise, someof the signal energy of the negative component of the phantom modesignal that is present on spring contacts 347-348 and mating contactpads 357-358 will capacitively couple from the contact pads 357-358through the dielectric substrate of printed circuit board 330 to theplate 370. In this manner, a reduced magnitude version of the positivecomponent of the phantom mode control signal (e.g., a magnitude that isreduced by 70 dB) is transferred to plate 360 and a reduced magnitudeversion of the negative component of the phantom mode control signal(e.g., a magnitude that is reduced by 70 dB) is transferred to plate370.

The positive and negative components of the reduced magnitude version ofthe phantom mode control signal are then coupled to the patch panelprinted circuit board 230 via their respective printed circuit boardtraces 362, 372, posts 364, 374, phantom mode contacts 366, 376 andcontact pads 265. From the contact pads 265, the phantom mode controlsignal may be provided to the phantom mode receiver 270 via circuittraces on the patch panel printed circuit board 230 (not shown on FIG.4B) and the multiplexer 290 (or other switching circuit). Thus, thecontact pads 351-352, 357-358, the plates 360, 370, the printed circuitboard traces 362, 372, the posts 364, 374, the phantom mode contacts366, 376, the contact pads 265, and the multiplexer 290 (and associatedtraces on patch panel printed circuit board 230) provide acommunications path that allows a phantom mode control signal that ispresent on the channel associated with jack 300 to be received anddemodulated (if necessary) by the phantom mode receiver 270 on the patchpanel 200. The same communications path from the multiplexer 290 to thespring contacts 341-342 and 347-348 may be used (in the reversedirection) to transfer phantom mode control signals that are generatedby the phantom mode transmitter 260 onto the spring contacts 341-342 and347-348 of pairs 2 and 4 of the jack 300.

While FIGS. 5A-5C illustrate one exemplary jack that includes circuitryfor capacitively coupling a phantom mode control signal to and/or fromthe contact wires 341-342 and 347-348 of pairs 2 and 4 of jack 300, itwill be appreciated that (1) any suitable connector port design may beused, (2) that numerous different control signal input circuits may beused to inductively and/or capacitively couple the phantom mode controlsignals to and from the channel at the connector port and/or (3) thatnumerous different capacitor designs may be employed which may result indifferent amounts of loss without departing from the scope of thepresent invention.

By way of example, in other embodiments, different control signal inputcircuits may be used that capacitively couple the phantom mode controlsignal directly to or from conductive traces on printed circuit board330, metal-plated apertures in printed circuit boards 330, and/or ontothe IDCs 368 and/or the spring contacts 341-348 that are mounted onprinted circuit board 330 as opposed to (or in addition to) using thecontact pads 351-352 and 357-358. Thus, it will be appreciated that thecontact pads 351-352 and 357-358 are not required, but merely provideone convenient way for capacitively coupling a phantom mode controlsignal to/from the phantom mode transmitter/receiver and the channel. Itwill likewise be appreciated that the plates 360, 370, the printedcircuit board traces 362, 372, the posts 364, 374, the phantom modecontacts 366, 376 and/or the contact pads 265 may be removed or replacedwith other structures. Likewise, the coupling structures could couple tosignal current carrying portions of the conductive paths through thejack 300 (as opposed to dead-end branches that are not on the directpath between spring contacts and their corresponding IDCs) such that thephantom mode control signal may be both capacitively and inductivelycoupled to or from the jack. Thus, it will be appreciated that thepresent invention is not limited to any particular circuit structurethat is used to, for example, capacitively couple the phantom modesignal to and/or from the jack 300.

FIGS. 6A-6B illustrate communications assemblies (or portions thereof)of communications connectors according to further embodiments of thepresent invention that illustrate additional exemplary changes that maybe made to the jack 300.

Turning first to FIG. 6A, a partial view of a printed circuit board330-1 of a communications assembly 320-1 is illustrated. Thecommunications assembly 320-1 may be used in place of the communicationsassembly 320 of FIGS. 5B-5C in the jack of FIG. 5A.

As shown in FIG. 6A, the communications assembly 320-1 is very similarto the communications assembly 320 that is discussed above with respectto FIG. 5B. In particular, communications assembly 320-1 includes aplurality of spring contacts 341-348 which may be identical to thespring contacts 341-348 that are discussed above with respect to FIG.5B.

The communications assembly 320-1 also includes a printed circuit board330-1 that is similar to the printed circuit board 330 that is discussedabove with reference to FIG. 5B. The printed circuit board 330-1 mayinclude traces/paths, crosstalk compensation circuits and aliencrosstalk compensation circuits, which are not shown to simplify thefigure. The printed circuit board 330-1 may further include contact pads351-358 and plates 360, 370 that are discussed above with reference toFIG. 5B. As these elements may be identical to their correspondinglynumbered elements in FIG. 5B, further description of these elements willbe omitted.

The printed circuit board 330-1 differs from the printed circuit board330, however, in that printed circuit board 330-1 further includes athird plate 361 and a fourth plate 371 that are embedded in an interiorlayer of the printed circuit board 330-1. The third plate 361 ispositioned under the contact pads 354-355 that electrically connect tothe conductors of pair 1, and the fourth plate 371 is positioned underthe contact pads 353 and 356 that electrically connect to the conductorsof pair 3. As contact pads 353 and 356 are not adjacent to each other,plate 371 comprises two smaller plates 371 a and 371 b that arepositioned underneath contact pads 353 and 356, respectively, that areconnected by a conductive connector 371 c. The callout in FIG. 6A is aplan view of the front portion of printed circuit board 330-1 thatbetter illustrates the shapes and locations of plates 360, 361, 370, 371in relationship to the contact pads 351-358.

As is further shown in FIG. 6A, conductive posts 364 and 374 areprovided on printed circuit board 330-1, and may be similar or identicalto the correspondingly numbered posts included in the printed circuitboard 330 of FIG. 5B. Plate 360 is electrically connected by a printedcircuit board trace 362 to the conductive post 364, and plate 370 iselectrically connected by a printed circuit board trace 372 to theconductive post 364 (which differs from printed circuit board 330, wheretrace 372 connects plate 370 a second conductive post 374). A secondconductive post 374 is provided, and a third printed circuit board trace363 is provided that electrically connects plate 361 to post 374 and afourth printed circuit board trace 373 is provided that electricallyconnects plate 371 to post 374. The conductive posts 364, 374 may beelectrically connected to respective phantom mode contacts 366, 376 (seeFIG. 5A) that mate with the respective contact pads 265 on patch panelprinted circuit board 230 that are associated with the jack 300.

The communications assembly 320-1 of FIG. 6A may operate as follows. Aphantom mode control signal may be coupled into the communicationsassembly via the phantom mode contacts 366, 376. In particular, thepositive component of the phantom mode control signal may be carried,for example, by phantom mode contact 366 and the negative component ofthe phantom mode control signal may be carried by phantom mode contact376. The positive component of the phantom mode control signal travelsthrough conductive post 364 and conductive traces 362, 372 to plates 360and 370, where it capacitively couples to contact pads 351-352 and357-358. So long as a plug is present in the plug aperture of jack 300(thereby resiliently deflecting the spring contacts 341-348 intophysical contact with their respective contact pads 351-358), then thecapacitively coupled component of the positive component of the phantommode control signal will be transferred onto the spring contacts 341-342and 347-348, where it can travel along the conductors of pairs 2 and 4of the patch cord inserted into jack 300 and along the conductors ofpairs 2 and 4 of any cable that is terminated into the back end of jack300. Similarly, the negative component of the phantom mode controlsignal travels from the phantom mode contact 376, through the contactpost 374 and conductive traces 363, 373 to plates 361 and 371, where itcapacitively couples to contact pads 353-356. So long as a plug ispresent in the plug aperture of jack 300 (thereby resiliently deflectingthe spring contacts 341-348 into physical contact with their respectivecontact pads 351-358), then the capacitively coupled component of thenegative component of the phantom mode control signal will betransferred onto the spring contacts 343-346 where it can travel alongthe conductors of pairs 1 and 3 of the patch cord inserted into jack 300and along the conductors of pairs 1 and 3 of any cable that isterminated into the back end of jack 300.

Thus, with the communications assembly 320-1 of FIG. 6A, a reducedmagnitude version of the positive component of the phantom mode controlsignal is transferred onto each of the four conductors included in pairs2 and 4 of the channel, and a reduced magnitude version of the negativecomponent of the phantom mode control signal is transferred onto each ofthe four conductors included in pairs 1 and 3 of the channel. The samecommunications path may be used (in the reverse direction) to transfer aphantom mode control signal that is carried into jack 300 on a patchcord or cable to the phantom mode contacts 366, 376, which can carry thesignal to a phantom mode receiver such as, for example, the phantom modereceiver 270 on the printed circuit board 230 of patch panel 200.

The printed circuit board 330-1 may be advantageous in someimplementations because it can be used to approximately double themagnitude of the phantom mode control signal that is coupled to and froma particular channel. In particular, in many cases the small printedcircuit boards that are commonly used in communications connectors suchas, for example, Category 6 and Category 6A RJ-45 jacks, can becomequite crowded or “real estate limited” due to the space required for theinput terminals, the output terminals, crosstalk compensation circuitsand the like. Additionally, care must be taken to appropriately locatethe various terminals, traces, circuits and the like with respect toeach other to avoid, for example, undesired capacitive and/or inductivecouplings between different elements on the printed circuit board thatmay negatively impact the crosstalk performance, return loss performanceor other performance characteristics of the connector. The aboveconsiderations may make it difficult to increase the size of thecapacitors that are used to capacitively couple the phantom mode controlsignal to and from the connector.

Unfortunately, since capacitive coupling is used to inject and extractthe phantom mode control signal from the channel, only a small portionof the phantom mode control signal is passed through the capacitor. Forexample, it is estimated that the capacitor formed by the plate 360 andthe contact pads 351, 352 will have a total injection capacitance ofapproximately 2×0.37 pF=0.74 pF. Such a capacitor value may be too lowto ensure that the received phantom mode control signal reception willbe distinguishable over other noise that may be added in the channel.Consequently, it may be desirable in certain embodiments to increase thecapacitance of the capacitors that are used to inject/extract thephantom mode control signals from the connectors according toembodiments of the present invention or to otherwise increase thecoupling (e.g., by increasing an inductive coupling element).

The capacitance of the printed circuit board capacitors that are used inthe illustrative embodiments provided above may be increased in avariety of ways. By way of example, the size of the plates 360, 370 andthe contact pads 351-352, 357-358 could be increased and/or thecapacitors could be implemented across multiple layers of the printedcircuit board to provide increased capacitance. However, theaforementioned crowding problems on printed circuit boards may limitthis option, as the larger capacitors may negatively impact variousperformance characteristics due to, for example, increased couplingbetween the larger capacitor electrodes and other elements on theconnector printed circuit board. While there are potential ways ofmitigating such performance degradation, including increasing the sizeof the printed circuit board or the number of layers included in theprinted circuit board, these solutions have their own potentialdrawbacks in terms of larger connector footprints and/or increasedconnector cost. Likewise, higher dielectric constant printed circuitsboards could be used, or special dielectric materials could be depositedon the printed circuit board between the electrodes of the capacitorsused in the control signal input circuit. These options, however, alsotend to increase the cost of the connector.

The printed circuit board 330-1 of FIG. 6A takes advantage of the factthat the phantom mode control signal may, if desired, be transmittedover all four differential pairs of conductors of jack 300 instead ofover only two of the differential pairs. In particular, with the printedcircuit board 330-1, one component of the phantom mode control signal(e.g., the positive component) is coupled onto all four conductors ofpairs 2 and 4 while the other component of the phantom mode controlsignal (e.g., the negative component) is coupled onto all fourconductors of pairs 1 and 3. While two additional capacitors (or othercoupling elements) are required to allow coupling one component of thephantom mode control signal onto (or off of) pairs 1 and 3, the contactpads 353-356 that are used to implement part of these capacitors mayalready be provided on the printed circuit board 330-1 in order tocouple the spring contacts 343-346 to crosstalk compensation capacitors(capacitors 333 in FIG. 5B) that are located near the front of printedcircuit boards 330 and 330-1. Thus, the only extra components requiredto add these capacitors are the plates 361, 371—which are located inotherwise unused real estate on the printed circuit board, and the smalltraces 363, 373. The number of added components using this method may befurther reduced, and the printed circuit board conductive trace artworkfurther simplified, by replacing plates 361 and 371 and the conductivetraces 363 and 372 connecting them to the contact post 374 with a singleplate that is positioned under, and spanning, the four contact pads353-356 and a single trace (e.g., trace 373) connecting this plate tothe contact post 374. Thus, pursuant to embodiments of the presentinvention, the amount of signal energy coupled to and from the connector300 on the phantom mode control channel may be approximately doubled byimplementing the phantom mode control signal on all four differentialpairs without requiring significant additional real estate on theprinted circuit board.

As the phantom mode control signal is injected as a differential signalhaving a component (e.g., the positive component) that is injected as acommon mode signal onto pairs 2 and 4, the differential informationsignals that are carried by pairs 2 and 4 will not be disturbed, as thiscommon mode component is subtracted off of each differential pair duringthe subtraction processes that are used to recover the respectivedifferential information signals. The component of the phantom modecontrol signal (e.g., the negative component) that is injected as acommon mode signal onto pairs 1 and 3 will likewise not disturb theunderlying differential information signals that are carried by pairs 1and 3 as this common mode component is subtracted off of eachdifferential pair during the subtraction processes that are used torecover the respective differential information signals.

As noted above, the capacitor formed by the contact pads 351, 352 andthe plate 360 and the capacitor formed by the contact pads 357, 358 andthe plate 370 that are provided on printed circuit board 330 of FIG. 5Bare referred to herein as 3-terminal capacitors as these capacitors havea total of three electrodes (e.g., contact pads 351 and 352 and plate360). In contrast, the capacitor formed by the contact pads 351, 352,357, 358 and the plates 360/370 and the capacitor formed by the contactpads 353, 354, 355, 356 and the plates 361/371 that are provided onprinted circuit board 330-1 of FIG. 6A are referred to as “5-terminalcapacitors” as these capacitors have a total of five electrodes (e.g.,contact pads 351, 352, 357 and 358 and the electrically interconnectedplates 360/370). Alternatively, each 5-terminal capacitor may be viewedas four separate capacitors.

Tables I-III below compare the simulated performance of a prototype jack300 that includes the communications assembly 320 versus anotherprototype jack that includes the communications assembly 320-1. Inparticular, Table I illustrates the capacitance values of the 3-terminaland 5-terminal capacitors (labeled “Capacitor 1” and “Capacitor 2” inTable I) that are used to inject/extract the phantom mode control signalfrom the connector. As shown in Table I, use of the 5-terminalcapacitors that are provided in communications assembly 320-1approximately doubles the capacitance. Table II illustrates the near endcrosstalk (“NEXT”) margins relative to the ISO connector specificationfor each combination of differential pairs. Here, the performance of thetwo prototype jacks is virtually indistinguishable for all paircombinations with the exception pairs 1 and 3, where the communicationsassembly 320-1 exhibits an improvement of over 1 dB in near endcrosstalk performance. Finally, Table III illustrates the return lossperformance for each pair of the communications assemblies 320 and320-1. As shown in Table III, the use of the 5-terminal capacitordesigns degrades the return loss on pairs 1 and 3 by about 0.5-1.0 dB,with somewhat smaller reductions on the other two pairs. However, thereturn loss on all four pairs is still well within the specifiedmargins.

TABLE I Capacitance of Phantom Mode Injection Circuit (pF) ConnectorCapacitor 1 Capacitor 2 Jack with Assembly 320 0.72 0.77 Jack withAssembly 320-1 1.80 1.49

TABLE II NEXT Margins (dB) for Each Pair Combination Connector 1&2 1&31&4 2&3 2&4 3&4 Jack with Assembly 5.66 0.08 −0.65 −0.45 6.48 0.65 320Jack with Assembly 5.66 1.25 −0.66 −0.45 6.46 0.64 320-1

TABLE III Return Loss Margins (dB) Connector Pair 1 Pair 2 Pair 3 Pair 4Jack with Assembly 320 2.98 6.55 2.67 4.37 Jack with Assembly 320-1 1.896.21 2.10 4.07

FIG. 6B is a schematic perspective view of a portion of a communicationsassembly 420 of an alternative jack that could be used to implement eachconnector port 220 on patch panel 200. The communications assembly 420differs from the communications assembly 320 in that it includes twoprinted circuit boards 430, 432 instead of the single printed circuitboard 330 provided in communications assembly 320. In communicationsassembly 420, the spring contacts 441-448 and IDCs (not shown) aremounted in printed circuit board 430, and the conductive traces/paths449 connecting the spring contacts 441-448 to the IDCs are likewiseprovided on printed circuit board 430. The printed circuit board 432includes contact pads 451-452, 457-458 and plates 460, 470 that may beidentical to contact pads 351-352, 357-358 and plates 360, 370 ofcommunications assembly 320. The communications assembly 420 furtherincludes conductive connections (not shown) that connect the plates 460,470 to the contact pads 265 on patch panel printed circuit board 230.

The jack 300 of FIGS. 5A-5C (or the alternative versions of the jack 300discussed with respect to FIGS. 6A-6B) provide examples of jacks thatcould be used as the connector ports 220 of patch panel 200 in order toprovide a communication system having the phantom mode control signalingcapabilities according to embodiments of the present invention. It willlikewise be appreciated, however, that the jacks of FIGS. 5A-5C andFIGS. 6A-6B may likewise be used in other environments such as, forexample, in consolidation points, as connector ports on a networkswitch, as modular wall jacks, and/or as the connector ports of enddevices. In each case, appropriate electrical connections would be madeto any phantom mode control signaling circuitry in a similar fashion tothe electrical connections that are shown above with respect to FIGS.5A-5C in order to connect the control signal input circuit on jack 300to the phantom mode control signaling circuitry on patch panel 200.

The discussion with respect to FIGS. 4A-4B, FIGS. 5A-5C and FIGS. 6A-6Billustrates several exemplary ways of implementing a patch panel havingphantom mode control signaling capabilities. A cross-connectcommunications patching system that uses, for example, theabove-described patch panel 200 of FIGS. 4A-4B that is populated withthe jacks 300 of FIGS. 5A-5C may automatically track patch cordconnections between two or more such patch panels 200 in the mannerdescribed above with respect to patch panels 110, 120 of FIG. 3 (i.e.,the patch panel 200 may be used to automatically track patch cordconnections in a cross-connect patching system). Pursuant to furtherembodiments of the present invention, the phantom mode control signalingtechniques disclosed herein may also be used to automatically trackpatching connections in inter-connect communications patching systemsand/or to track patching connections between patch panels and networkswitches such as, for example, the patch panel 120 and switch 130 ofFIG. 3.

In particular, FIG. 7 is a schematic view of an inter-connectcommunications system 11 according to certain embodiments of the presentinvention that may be used to connect computers, printers, Internettelephones and other end devices that are located in work areasthroughout a building to network equipment that is located, for example,in a computer room of the building. The exemplary inter-connectcommunications system 11 depicted in FIG. 7 is quite similar to theexemplary cross-connect communications system 10 illustrated in FIG. 2,and hence like reference numerals will be used to identify like elementsin these figures, and the description below will focus on thedifferences between the systems 10, 11 depicted in FIGS. 2 and 7,respectively.

Specifically, as shown in FIG. 7, the inter-connect communicationssystem 11 omits the second equipment rack 30′ that is provided in thecross-connect communication system 10 of FIG. 2. Consequently, in thecommunications system 11 of FIG. 7, the connector ports 34 on the patchpanels 32 on equipment rack 30 are directly connected to respective onesof the connector ports 44 on the network switches 42 by the first set ofpatch cords 50. Connectivity changes are typically made in thecommunication system 11 by rearranging the patch cords 50 thatinterconnect the patch panels 32 and the network switches 42.

Unfortunately, network switches are not available that include thephantom mode control signal circuitry discussed above that may beprovided on the patch panels according to embodiments of the presentinvention. As such, pursuant to further embodiments of the presentinvention, “interposer” communications connectors are provided that maybe used on network switches or other network equipment (and also on workarea end devices, as will be discussed below) to facilitateautomatically tracking patching connections and/or automaticallyidentifying end devices according to certain embodiments of the presentinvention.

FIGS. 8A-8D illustrate one exemplary interposer 500 according toembodiments of the present invention. FIG. 8A is a schematic perspectiveview of the interposer 500 that includes six (6) connectors 510, FIG. 8Bis a top view of a communications assembly 520 of one of the connectors510 of interposer 500, and FIG. 8C is a side view of the communicationsassembly 520 of FIG. 8B. FIG. 8D is a schematic block diagram thatillustrates a phantom mode control signal circuit that may be includedwithin or on the interposer 500.

Referring first to FIG. 8A, it can be seen that interposer 500 includesa plurality of connectors 510. Each connector 510 comprises acombination plug-jack connector that includes a plug end 512 that isterminated with a communications plug (e.g., an RJ-45 plug) and a jackend 514 that is terminated with a communications jack (e.g., an RJ-45jack). Each plug-jack connector 510 may comprise a communicationsassembly 520 (see FIGS. 8B-8C) and a protective dielectric housing 515.The plug end 512 of each plug-jack connector 510 may be plugged into aconnector port (e.g., an RJ-45 jack) on a network switch or other pieceof network equipment. While the interposer 500 includes a total of sixplug-jack connectors 510 that are linearly arranged, it will beappreciated that interposers may be provided that have any number ofplug-jack connectors 510, and that the spacing and arrangement of theconnectors 510 may be varied. Typically, the number, spacing andarrangement of the connectors 510 on interposer 500 will be designed tomatch the number, spacing and arrangement of the connector ports on thenetwork equipment that the interposer 500 is to be used with. As will beexplained in more detail below, the interposer 500 may include circuitrythat facilitates sending and/or receiving phantom mode control signals,and thus the interposer 500 may facilitate tracking patching connectionsbetween network switches and patch panels such as the connections formedby patch cords 50 in the interconnect communications system 11 of FIG.7. It will also be appreciated that interposers 500 may be used on workarea end devices and or network end devices in addition to on networkswitches.

Turning now to FIGS. 8B-8C, it can be seen that the jack end portion 514of each communications assembly 520 may be nearly identical to thecommunications assembly 320 of jack 300 of FIGS. 5A-5C. The primarydifference between the communications assembly 320 of jack 300 and thecommunications assembly 520 of connector 510 is that assembly 520 doesnot include any IDCs. Instead, in communications assembly 520, theconductive printed circuit board traces/paths 349 of printed circuitboard 530 electrically connect the respective spring contacts 541-548 toa plurality of plug blades 570 that are provided on the plug end 512 ofassembly 520. Note that the spring contacts 541-548 are shownschematically in FIG. 8B (and hence the crossovers therein are notillustrated in FIG. 8B). Any appropriate design may be used for springcontacts 541-548, specifically including the design of contacts 341-348of jack 300 of FIGS. 5A-5C. It will also be appreciated that theconnector 510 will typically include other appropriate circuitry such ascrosstalk compensation circuits.

When the plug end 512 of connector 510 is inserted into a connector porton the network switch, the plug blades 570 and conductive printedcircuit board traces 349 electrically connect the spring contacts of theconnector port on the network switch to the spring contacts 541-548 ofconnector 510. While not visible in FIGS. 8A-8C, connector 510 furtherincludes the contact pads 351-352 and 357-358 and plates 360, 370 thatare discussed above with respect to jack 300, which operate in the samemanner described above with respect to FIGS. 5A-5C.

Referring now to FIG. 8D, it can be seen that the interposer 500 mayinclude circuitry similar to the circuitry included on patch panelprinted circuit board 230. In particular, the interposer 500 may alsoinclude a phantom mode transmitter 560, a phantom mode receiver 570, amicroprocessor 580 and a multiplexer 590. While these components are notillustrated in FIGS. 8A-8C in order to simplify the drawings, it will beappreciated that they can be built in or added to the interposer 500 ina variety of ways. For example, in one embodiment, the connectors 510 ofinterposer 500 could be designed to share a single, common printedcircuit board (in the embodiment depicted in FIGS. 8A-8C each connector510 includes its own printed circuit board 530), and the phantom modetransmitter 560, phantom mode receiver 570, microprocessor 580 andmultiplexer 590 could be mounted on this common printed circuit boardand connected by conductive traces/paths to plates similar to the plates360, 370 shown in FIGS. 5B-5C. In such an embodiment, features similarto the printed circuit board traces 362, 372, the conductive posts 364,374 (or, alternatively, metal-plated vias) and the phantom mode contacts366, 376 of FIGS. 5A-5C could potentially be omitted from the interposer500. In other embodiments, the phantom mode transmitter 560, phantommode receiver 570, microprocessor 580 and multiplexer 590 could bemounted on a separate “phantom mode” printed circuit board that isconnected, for example, to the top sides or the bottom sides of theconnector housings 515. In such an embodiment, additional circuitry willbe necessary that electrically connects the phantom mode circuit boardto the printed circuit boards 530 of the individual connectors 510 sothat the phantom mode control signals may be passed between theindividual connectors 510 and the phantom mode circuitry on the phantommode circuit board.

In any event, regardless of the specific implementation, each connector510 on interposer 500 may include a pair of conductive paths thatelectrically connect the respective plates 360, 370 (see FIG. 5C) to themultiplexer 590 (or other selective switching circuit). One suchexemplary pair of conductive paths is illustrated in the schematic blockdiagram of FIG. 8D. It will thus be understood that the interposer 500may be used to upgrade a network switch to have the capability totransmit and/or receive phantom mode control signals in the same fashionthat the patch panel 200 described above can transmit and/or receivephantom mode control signals to automatically track patchingconnections. Given that a network switch that includes an interposer 500may function in exactly the same manner as the patch panel 200 describedabove, further discussion of the operation of the interposer 500 will beomitted.

It will be appreciated that the phantom mode transmitters 260, 560, thephantom mode receivers 270, 570, the microprocessors 280, 580 and themultiplexers 290, 590 that are described above may all comprise activecomponents that require a direct current operating voltage. Currentintelligent patch panels (i.e., patch panels that have the ability toautomatically track patching connections) already typically includeactive components, and connections for providing power to suchintelligent patch panels are already well known in the art and need notbe described further herein. Power may be provided to the phantom modetransmitter 560, the phantom mode receiver 570, the microprocessor 580and the multiplexer 590 of interposer 500 in a variety of ways. Forexample, in some embodiments a power cord may be used that connects theactive circuits on interposer 500 to a power or operating voltageconnection on the equipment rack on which the network switch that theinterposer 500 is used with is mounted. In other embodiments,Power-over-Ethernet technology may be used to provide power to theactive components of interposer 500.

It should be noted that the interposer 500 preferably should be nearlyinvisible electrically so that the inclusion of the interposer 500 doesnot appear as another connection in the channel. This may beaccomplished, for example, by designing different interposers 500 foruse with different network switches, where the connector 510 isspecifically tuned to provide a high degree of crosstalk cancellationand low return losses when used in the connector port on the switch atissue.

It will also be appreciated that the interposer 500 depicted in FIGS.8A-8D simply illustrates one possible interposer design, and thatnumerous other interposers could be used in place of the interposer 500.By way of example, FIGS. 23A and 23B illustrate an interposer 1200according to further embodiments of the present invention. Inparticular, FIG. 23A is a schematic block diagram of an interposer 1200,while FIG. 23B is a schematic diagram illustrating the electricalconnections for one of the patch cords (not shown) that is connected toa network device using the interposer 1200. The interposer 1200 may beused to track patching connections between network switches and patchpanels such as the connections formed by patch cords 50 in theinterconnect communications system 11 of FIG. 7. It will also beappreciated that interposers 1200 may be used on work area end devicesand or network end devices in addition to on network switches.

As shown in FIGS. 23A and 23B, the interposer 1200 includes a printedcircuit board 1210. In the particular embodiment shown, the eightconductors (not shown) of each of six patch cords 1230 (i.e., a total of48 conductors) are terminated into respective wire connection terminalssuch as insulation piercing contacts or IDCs that are mounted in theprinted circuit board 1210. While the wire connection terminals are notshown in FIGS. 23A and 23B to simplify the diagrams, apertures 1212 inwhich the eight wire connection terminals for one of the six patch cordsare illustrated in FIG. 23B. Each patch cord 1230 may comprise astandard patch cord. However, in the embodiment of FIGS. 23A and 23B,the patch cords 1230 would only have a plug connector on one sidethereof, since the conductors of the patch cord are connected to theprinted circuit board 1210 using wire connection terminals such asinsulation piercing contacts or IDCs.

The interposer 1200 also include a plurality (here 6) of plug connectors1220 that each include eight plug blades 1221. Each plug connector 1220acts as the plug connector for a respective one of the patch cords 1230.While not shown in FIG. 23A-23B, each plug connector 1220 would includea conventional RJ-45 plug housing and would be configured to mate with aconventional RJ-45 connector port on, for example, a network switch. Asshown in FIG. 23B, the aperture 1212 for each wire connection terminalfor a particular patch cord 1230 is connected to a respective one of theplug blades 1221 for its corresponding plug connector 1220, therebyproviding the electrical connections between each patch cord 1230 and aconnector port that the patch cords respective plug connector 1220 isplugged into.

The spacing between the plug connectors 1220 may be designed to matchthe spacings between connector ports on conventional network switches(note that more than one design would be necessary as different switchmanufacturers have different connector port configurations). The printedcircuit board 1210 may also be encased in a protective housing (notshown) that may hold the conductors of the patch cords 1230 in placeonce those conductors are attached to their respective wire connectionterminals. While the interposer 1200 includes a total of six plugconnectors 1220 that are linearly arranged, it will be appreciated thatinterposers 1200 may be provided that have any number of plug connectors1220, and that the spacing and arrangement of the plug connectors 1220may be varied.

As is also shown in FIG. 23A, a phantom mode transmitter 1260, a phantommode receiver 1270, a microprocessor 1280 and a multiplexer 1290 may bemounted on the printed circuit board 1210 and interconnected byconductive traces on the printed circuit board 1210. The phantom modetransmitter 1260, the phantom mode receiver 1270, the microprocessor1280 and the multiplexer 1290 may be identical to the phantom modetransmitter 560, phantom mode receiver 570, microprocessor 580 andmultiplexer 590 of the interposer 500 of FIGS. 8A-D, and henceadditional description of these components and the operation thereofwill be omitted here. As shown in FIG. 23A, the multiplexer 1290 has apair of outputs for each plug connector 1220 that are connected torespective ones of a pair of conductive plates 1213, 1214 for each plugconnector 1220 (that the multiplexer outputs and conductive plates 1213,1214 are illustrated for only one of the six plug connectors 1220 inFIG. 23A to simplify the drawing).

FIG. 23B illustrates how the conductive plates 1213, 1214 may be used tocouple a phantom mode control signal from phantom mode transmitter 1260onto two of the differential pairs of one of the plug connectors 1220.As shown in FIG. 23, the conductive plates 1213 that receive the firstcomponent (e.g., the positive component) of a phantom mode controlsignal are electrically connected to each other by a trace 1215.Likewise, the conductive plates 1214 that receive the second component(e.g., the negative component) of the phantom mode control signal areelectrically connected to each other by a trace 1216. Additionally, theconductive traces 1211 for a first of the differential pairs (i.e., thetraces that connect each wire connection terminal of the pair to itsrespective plug blade) each have a widened area 1217 that is locateddirectly above a respective one of the conductive plates 1213. Theplates 1213 and the widened areas 1217 act like plate capacitors tocouple the first component of a phantom mode control signal transmittedby phantom mode transmitter 1260 onto the first differential pair (andhence into the channel). The conductive traces 1211 for a second of thedifferential pairs each similarly have a widened area 1218 that islocated directly above a respective one of the conductive plates 1214.The plates 1214 and the widened areas 1218 also act like platecapacitors that may be used to couple the second component of thephantom mode control signal transmitted by phantom mode transmitter 1260onto the second differential pair (and hence into the channel). Thesestructures likewise may be used to couple a phantom mode control signalfrom the channel to the phantom mode receiver 1270 through multiplexer1290.

Thus, the interposer 1200 can be used to upgrade a network switch or anend device to have the capability to transmit and/or receive phantommode control signals in the same fashion that the patch panel 200described above can transmit and/or receive phantom mode control signalsto automatically track patching connections. Given that a network switchthat includes an interposer 1200 may function in exactly the same manneras the patch panel 200 described above, further discussion of theoperation of the interposer 1200 will be omitted.

The interposer 1200 may have an advantage over the interposer 500 inthat it can more easily be designed to be nearly invisible electricallyso that the inclusion of the interposer 1200 does not appear as anotherconnection in the channel (this may be more difficult with theinterposer 500 of FIGS. 8A-D). However, the interposer 1200 requires anadded installation step, as the six patch cords must be manuallyterminated into the wire connection terminals of the interposer 1200. Anappropriate interposer design may be selected based on theconsiderations of any given communications system.

Pursuant to further embodiments of the present invention, circuits maybe provided that can be used to detect the insertion and/or removal ofpatch cords at various connector ports in a communications channel. Byautomatically identifying such plug insertions and removals, theconnection tracking systems according to embodiments of the presentinvention may operate as event-driven systems and may generateadditional tracking information that may be used by, for example,network administrators.

FIG. 9 is a simplified perspective view of a communications assembly 620of a jack 600 that includes a plug insertion/removal detection circuit690. The jack 600 may be identical to the jack 300 discussed above withrespect to FIGS. 5A-5C (or to the alternative embodiments thereof shownin FIGS. 6A-6B) except that the jack 600 additionally includes the pluginsertion/removal detection circuit 690. In order to simplify thedrawings, all of the internal electrical connections on the printedcircuit board 630 of communications assembly 620 have been omitted inFIG. 9 except for the electrical connection to the pluginsertion/removal detection circuit 690. It will also be appreciatedthat the plug insertion/removal detection circuit 690 may be implementedon any other conventional or non-conventional jack. In some embodiments,the jack 600 may be used, for example, as one of the connector ports 220on patch panel 200, as a connector port that is used in a modular walljack or consolidation point (e.g., wall jack 140 of FIG. 2), as one ofthe connectors 510 (suitably modified to have a plurality of plug bladeoutput terminals as opposed to IDCs) of interposer 500, or as aconnector port of an interposer that is installed on a work area ornetwork end device. Typically, the jack 600 will have an associatedphantom mode transmitter, phantom mode receiver and microprocessor (notshown in FIG. 9). By way of example, if the jack 600 is used as one ofthe connector ports on patch panel 200, the jack 600 may operate inconjunction with the phantom mode transmitter 260, phantom mode receiver270 and microprocessor 280 that are mounted on patch panel printedcircuit board 230.

As shown in FIG. 9, the communications assembly 620 includes a printedcircuit board 630. The plug insertion/removal detection circuit 690comprises an externally accessible contact 692 and a conductive trace694 that may be implemented on printed circuit board 630. The conductivetrace 694 is physically and electrically connected to a spur off of oneof the conductive paths that connects spring contact 348 to itscorresponding IDC. Consequently, any signal that is present on springcontact 348 will flow through conductive trace 694 to the externallyaccessible contact 692. The plug insertion/removal detection circuit 690further includes a contacting structure 696 (which is schematicallydepicted and only partially shown in FIG. 9) that electrically connectsthe externally accessible contact 692 to the microprocessor 280 via themultiplexer 290 (not shown in FIG. 9). In the depicted embodiment, thecontact 692 is located near the front of the printed circuit board 630so that the externally accessible contact 692 may be in close proximityto the patch panel printed circuit board 230 on which multiplexer 290may be mounted. As further shown in FIG. 9, the communications assembly620 may also include a second externally accessible contact 692′, asecond conductive trace 694′ and a second contacting structure 696′ thatare identical to elements 692, 694 and 696, respectively, except thatthey are connected to one of the conductive paths of a different one ofthe differential pairs of conductive paths through the communicationsassembly 620. These additional structures 692′, 694′ and 696′ may beused to map horizontal cabling connections, as will be discussed infurther detail later in this application

Operation of the plug insertion/removal detection circuit 690 will nowbe described with reference to FIGS. 4A-4B, 5A-5C and 9.

When the phantom mode transmitter 260 transmits a phantom mode controlsignal to the jack 600, that signal is input to the plates 360, 370 ofjack 600 via the contact pads 265 on the patch panel printed circuitboard 230, the phantom mode contacts 366, 376, the conductive posts 364,374 and the circuit traces 362, 372. If a plug is inserted within theplug aperture of jack 600, then the spring contacts 341-348 will bedeflected downwardly to come into contact with the contact pads 351-358in the manner discussed above with reference to FIGS. 5A-5C. In such acase, the phantom mode control signal that is input from the phantommode transmitter 260 to the plates 360, 370 is capacitively coupled tothe pads 351-352 and 357-358, where it is then coupled to the springcontacts 341-342 and 347-348. This capacitively coupled phantom modecontrol signal, which may have a magnitude that is, for example, on theorder of 70 dB less than the magnitude of the phantom mode controlsignal that is input to jack 600, is then coupled onto the conductivetraces/paths 349 (only one of which is shown in FIG. 9) associated witheach of spring contacts 341-342 and 347-348, and hence will travel tothe externally accessible contact 692 and contacting structure 696(since contact 692 and contacting structure 696 are electricallyconnected to the conductive path through the jack 600 that connectsspring contact 348 to its respective IDC). As discussed above, thecontacting structure 696 connects the externally accessible contact 692to an input port on the microprocessor 280. Thus, if a plug is receivedwithin the plug aperture of jack 600, a phantom mode control signal thatis generated by phantom mode transmitter 280 and injected into jack 600via the plates 360, 370 will pass back out of the jack via contactingstructure 696 and is fed to the microprocessor 280, where it can bedetected.

If, on the other hand, a plug is not inserted within the plug apertureof jack 600, then the spring contacts 341-348 will remain in theirnormal resting position where they do not come into contact with thecontact pads 351-358 (which are shown best in FIG. 5B, and which arealso present in FIG. 9, but hidden from view by the distal ends of thespring contacts 341-348). As such, the phantom mode control signal thatis input from phantom mode transmitter 260 to the plates 360, 370 is notcapacitively coupled onto the spring contacts 341-342 and 347-348, andhence no phantom mode control signal will travel to the microprocessor280 via the externally accessible contact 692 and contacting structure696 and other connecting structures.

In light of the above operating characteristics, the microprocessor 280may use the signal provided via the contacting structure 696 to make adetermination as to whether or not a plug is presently inserted in jack600. This determination may be performed in a variety of different ways.In some embodiments, the microprocessor 280 may perform an analogcomparison of the relevant portion (e.g., positive or negative) of thephantom mode control signal that it provides to the jack 600 with anysignal that is present on the contacting structure 696. By way ofexample, if the phantom mode control signal that is injected into thephantom mode control channel of jack 600 comprises a 50 MHz FSKmodulated signal, the presence of the positive or negative component ofsuch a 50 MHz FSK modulated signal on the contacting structure 696(reduced in magnitude due to the capacitive coupling) may indicate thata plug is currently inserted in the plug aperture of jack 600, sincesuch a signal should not be present if no plug is inserted because theinjected phantom mode control signal will only be injected onto thespring contacts if a plug is present in the plug aperture and thereforeforcing the spring contacts 341-348 into direct contact with the contactpads 351-358.

In other embodiments, the signal present on contacting structure 696 maybe provided to the phantom mode receiver 270 where it is demodulated.The demodulated baseband packetized digital data stream may be comparedto the digital data stream that was sent by the phantom mode transmitter260 to jack 600 or, alternatively, can be scanned for identificationinformation embedded therein that indicates that the signal originatedfrom the patch panel associated with jack 600. In this manner, themicroprocessor 280 may reliably identify plug insertions and removalsfrom the plug aperture of jack 600.

As should be clear from the above discussion, in some embodiments, thecommunications jack 600 may include a plurality of spring contacts341-348 that have plug contact regions that comprise input ports of thejack 600 and a plurality of wire connection contacts that include wirecontact regions that comprise output ports of the jack 600. A pluralityof conductive paths 349 (e.g., printed circuit board traces and layertransferring structures) may connect respective ones of the springcontacts to respective ones of the wire connection contacts. Theseconductive paths 349 may be arranged as a plurality of differentialpairs of conductive paths. A control signal input circuit such as acapacitor may be provided that is used to inject a common mode controlsignal onto a first of the differential pairs of conductive paths. Acontrol signal output circuit is provided (e.g., an externallyaccessible contact 692 and/or contacting structure 696) that isconfigured to output at least a portion of the injected common modecontrol signal. A plug insertion detection circuit is provided (e.g.,the phantom mode receiver and associated processor) that is coupled tothe control signal output circuit.

As should be clear from the above discussion, the plug insertion/removaldetection circuit 690 may detect the presence or absence of a plugregardless of whether or not the far end of the patch cord that includesthe plug in question is plugged into another connector port. This may beadvantageous in that it may, for example, help network administratorsidentify improperly installed patch cords where one of the plugs on thepatch cord was not fully inserted into the plug aperture on theconnector port the plug was supposed to mate with. Moreover, the pluginsertion/removal detection circuit 690 may be implemented quitecheaply. In the depicted embodiment, all that is required are a trace694, a contact pad 692 and a contacting structure 696, each of which maybe very inexpensive, along with software that analyzes the signalreceived on contacting structure 696 to determine if it corresponds tothe transmitted phantom mode signal (or a component thereof).

Approaches that demodulate the signal present on contacting structure696 and extract unique data therefrom may be preferred in embodimentswhere more than one phantom mode transmitter is provided along achannel, to avoid the possibility that the microprocessor 280 detects aphantom mode control signal on contacting structure 696 that wasinjected by a phantom mode transmitter other than the phantom modetransmitter associated with microprocessor 280 (i.e., the phantom modetransmitter 260). In addition, noise and/or electromagnetic interferencemay be present that may distort the above-described direct analogcomparison (particularly as the capacitively coupled phantom modecontrol signal may be reduced in magnitude on the order of 70 dB andhence more susceptible to noise). The impact of such noise may bereduced by demodulating the received signal.

A method of detecting the insertion and/or removal of a plug from acommunications connector according to embodiments of the presentinvention will now be described with reference to the flow chart diagramof FIG. 18. This method may be performed, for example, using the pluginsertion/removal detection circuit 690 depicted in FIG. 9.

As shown in FIG. 18, operations may begin with a control signal beingtransmitted to a control signal input circuit of the communicationsconnector (block 1000). This control signal may then beelectromagnetically coupled through the control signal input circuit(block 1005). A determination may then be made as whether or not theelectromagnetically coupled control signal is present on a firstdifferential pair of conductive paths that are included in thecommunications connector (block 1010). If they are not, operations mayproceed back to block 1000. If it is determined at block 1010 that theelectromagnetically coupled control signal is present on the firstdifferential pair of conductive paths, then a determination is made thata mating plug is present in the plug aperture (block 1015). Thisdetermination may be based at least in part on detecting theelectromagnetically coupled control signal on the first differentialpair of conductive paths through the communications connector.

In some embodiments, the control signal may be a common mode controlsignal that is electromagnetically coupled onto both conductive paths ofthe first differential pair of conductive paths. In some embodiments, asecond control signal may be electromagnetically coupled from a secondcontrol signal input circuit onto a second differential pair ofconductive paths through the connector, and the control signal and thesecond control signal may together comprise a differential controlsignal such as, for example, a phantom mode control signal. In suchembodiments, the control signal input circuit may be a firstthree-terminal capacitor that electromagnetically couples a firstcomponent of the phantom mode control circuit onto the firstdifferential pair of conductive paths and a second three-terminalcapacitor that electromagnetically couples the a second component of thephantom mode control circuit onto the second differential pair ofconductive paths.

It will be appreciated that the plug insertion/removal detection circuit690 depicted in FIG. 9 is exemplary in nature, and that numerouspossible modifications thereto are possible. For example, while theexternally accessible contact 692 is implemented as a contact pad on thelower surface of the jack printed circuit board 630 in the depictedembodiment, it will be appreciated that any conductive contact can beused such as, for example, a conductive post or a metal plated aperturethat receives the contacting structure 696 (e.g., the contactingstructure 696 may include an eye-of-the-needle termination that ismounted in such a metal-plated aperture in printed circuit board 630).It will likewise be appreciated that the conductive trace 694 may have adifferent configuration or may be omitted (i.e., if the externallyaccessible contact 692 or contacting structure 696 is connected directlyto the conductive path for spring contact 348). It will likewise beunderstood that the plug insertion/removal detection circuit 690 mayconnect directly to a portion of the conductive path for spring contact348 that is not on the printed circuit board 630 such as, for example,the spring contact 348 or its corresponding IDC. Moreover, while theplug insertion/removal detection circuit 690 is depicted as connectingto the conductive path for spring contact 348, it will be appreciatedthat it can be implemented as any circuit that provides access to one ormore of the conductive paths through jack 600 that are configured tocarry a phantom mode control signal so that the path may be monitored todetermine if a control signal is in fact present. While in the aboveexample, a conductive trace 694 is used to connect the externallyaccessible contact 692 to the conductive path 349 that connects theappropriate spring contact to the corresponding IDC, it will beappreciated that a capacitor can used instead. Such a capacitor can beimplemented in a number of ways such a for example by depositingparallel plates on different layers of the printed wiring board.

As another example, the plug insertion/removal detection circuit 690depicted in FIG. 9 could be modified to provide a differential pluginsertion/detection signal that is less immune to noise. For instance, asecond externally accessible contact 692′ (not shown), a secondconductive trace 694′ (not shown), and a second contacting structure696′ (not shown), that may be substantially identical to contacts andtraces 692, 694, 696, except that contacts/traces 692′, 694′, 696′ areelectrically connected to a spur off of one of the conductive paths thatconnects, for example, spring contact 341 to its corresponding IDC. Insuch an embodiment, the plug insertion/removal detection signal willcomprise a differential signal in that it will include, for example, thepositive component of the phantom mode control signal on externallyaccessible contact 692′ and the negative component of the phantom modecontrol signal on externally accessible contact 692. This differentialplug insertion/removal detection signal may then be fed to themicroprocessor 280 via, for example, the multiplexer 290. The use of adifferential plug insertion/removal detection signal may be preferred insome embodiments because it may be less susceptible to corruption bynoise.

It will also be appreciated that different signals may be transmittedover the phantom mode control channel for purposes of detecting pluginsertions/removals versus phantom mode control signals that aretransmitted to identify patching connectivity. Moreover, in someembodiments, each patch panel, interposer and other device on a channelthat has a phantom mode transmitter may use a different frequency totransmit the phantom mode control signals that are used to detect pluginsertions and removals by setting the phantom mode transmitter on eachsuch device to transmit, for example, at slightly different frequencies.Such an approach may be advantageous because the phantom mode controlsignals that are transmitted on a channel may traverse the entirechannel, and hence in some cases it may not otherwise be apparent whichphantom mode transmitter is transmitting a plug insertion/removaldetection signal. By having the phantom mode transmitters transmit atpre-defined frequencies, the frequency of the received signal may beused to identify the corresponding transmitter, which in turn may beused to determine which connector port along a channel a plug wasinserted into. In other embodiments, other identification means may beused such as, for example, having each phantom mode transmitter includea unique identifier when sending a plug insertion/removal detectionsignal.

FIGS. 10A-10B are schematic diagrams that illustrate a jack 300-1 thatincludes a plug insertion/removal detection circuit 700-1 according tofurther embodiments of the present invention that may be used to detectwhen a plug is inserted into, or removed from, a connector port. Thejack 300-1 may be identical to the jack 300 of FIGS. 5A-5C (or themodified versions of jack 300 explained above with reference to FIGS.6A-6B) with the exception that the jack 300-1 further includes the pluginsertion/removal detection circuit 700-1, and hence further descriptionof the features of jack 300-1 will be omitted herein. FIG. 10C is ablock diagram illustrating how the phantom mode control signallingcircuitry may be used to send an excitation signal to the pluginsertion/removal detection circuit 700-1.

Starting first with FIG. 10A, this schematic front view of the plugaperture of jack 300-1 illustrates the positions of the distal ends ofspring contacts 341-348 when no plug is inserted in the plug aperture313 of jack 300-1. As shown in FIG. 10A, structures such as conductiveposts, plates or the like 302, 304 may be mounted on or embedded in theprinted circuit board 330 on either side of the spring contacts 341-348(or alternatively, mounted on sidewalls of the jack housing or in anyother appropriate manner). These conductive structures 302, 304 may beviewed as two electrodes of a capacitor. The dielectric constant of thewhatever is between the structures 302, 304 will necessarily changebased on whether or not the spring contacts 341-348 have or have notbeen deflected downwardly to reside between the structures 302, 304. Asshown in FIG. 10A, if no plug is received within the plug aperture 313of jack 300-1, then air is disposed between the structures 302, 304, andhence the dielectric constant of the capacitor formed by structures 302,304 and the air therebetween will be the dielectric constant of air(here secondary effects, such as the effect the top surface of printedcircuit board 330 will have on the dielectric constant, are ignored tosimplify the explanation).

FIG. 10B is a similar schematic front view of the plug aperture of thejack 300-1 that illustrates the positions of the distal ends of springcontacts 341-348 when a plug is present in the plug aperture 313 of jack300-1. As shown in FIG. 10B, when a plug is present, the distal endportions of the spring contacts 341-348 are forced downwardly toward theprinted circuit board 330 so that they occupy the space between theconductive structures 302, 304. When this occurs, the dielectricconstant for the capacitor formed by structures 302, 304 changes, as thespring contacts 341-348 have a dielectric constant that differs from thedielectric constant of air.

Referring now to the block diagram of FIG. 10C, a control signal can betransmitted to structure 302 from, for example, the phantom modetransmitter 260 of patch panel 200. The phantom mode transmitter 260 maybe coupled to structure 302 via any appropriate electrical connectionsuch as, for example, the multiplexer 290 (see FIG. 4B), the contacts265 (see FIG. 4B), the phantom mode contact 366 (see FIG. 5A), the post364 (see FIG. 5B) and a conductive trace (not shown in the figures) thatconnects the post 364 to structure 302. Some portion of the signal fromthe phantom mode transmitter 260 that is received at structure 302 iscapacitively coupled to structure 304. The signal that is received onstructure 304 may then be provided to for example, the phantom modereceiver 270 and/or processor 280 of patch panel 200 via any appropriateelectrical connection such as, for example, a conductive trace (notshown in the figures) that connects the structure 304 to the post 374(see FIG. 5B) so that the signal may be passed to the phantom modecontact 376 (see FIG. 5A), to the contacts 265 (see FIG. 4B) to themultiplexer 290 (see FIG. 4B) and on to the phantom mode receiver 270.As the magnitude of the received signal will vary based on whether ornot the spring contacts 341-348 are in the position of FIG. 10A or inthe position of FIG. 10B due to the above-described variation in thedielectric constant, the magnitude of the signal received on structure304 that is passed on to the phantom mode receiver 270 may be used todetermine whether or not a plug is inserted in the plug aperture 313 ofjack 300-1.

Note that it may be necessary to take steps to ensure that the magnitudeof the signal on structure 304 that is measured is the signal energy ofthe signal that was transmitted to structure 302 that capacitivelycouples to structure 304. This may be accomplished in some embodimentsby, for example, transmitting the signal to structure 302 at anout-of-band frequency (e.g., 800 MHz) and then filtering out otherfrequencies at the receiver in order to measure the magnitude of thesignal that is capacitively coupled to structure 304.

FIGS. 11A-11B are schematic diagrams that illustrate a jack 300-2 thatincludes another plug insertion/removal detection circuit 700-2 that issimilar to the circuit 700-1 shown in FIGS. 10A-10B. In particular, FIG.11A is a schematic front view of a jack 300-2 with no plug insertedtherein, and FIG. 11B is a schematic front view of a jack 300-2 with aplug inserted in the plug aperture. The plug detection circuit 700-2 maybe coupled to the phantom mode transmitter 270 and the phantom modereceiver 260 in the same manner, discussed above with reference to FIG.10C, that plug detection circuit 700-1 is coupled to the phantom modetransmitter 270 and the phantom mode receiver 260.

As shown in FIGS. 11A-11B, the plug insertion/removal detection circuit700-2 comprises a first plate 302′ of a capacitor that is mounted at thetop of the plug aperture and a second plate 304′ of the capacitor thatis mounted at the bottom of the plug aperture. The pluginsertion/removal detection circuit 700-2 may operate in essentially thesame fashion as the plug insertion/removal detection circuit 700-1 ofFIGS. 10A-10B. In particular, the dielectric constant of the pluginsertion/removal detection circuit 700-2 changes based on whether ornot a plug or air is present in the plug aperture. An out-of-bandcontrol signal is transmitted to plate 302′, and some portion of thatcontrol signal is capacitively coupled to plate 304′. The signal onplate 304′ may then be provided to a receiver where, for example, themagnitude of the received signal is determined. As the magnitude of thereceived signal will vary based on the dielectric constant of thematerial (i.e., either air or a plug) that is present in the plugaperture, the magnitude of the received signal may be used to determinewhether or not a plug is inserted in the plug aperture 313 of jack300-2.

While FIGS. 11A-11B illustrate an embodiment in which the structures302′, 304′ are located at the top and bottom of the plug aperture, itwill be appreciated that these structures may be located in differentpositions and/or sized differently in various alternative embodiments.By way of example, in one alternative embodiment the structures 302′,304′ may be located on the opposing left and right sides of the plugaperture 313.

It should also be noted that the plug insertion/removal detectioncircuit 700-2 of FIGS. 11A-11B works on fiber optic connectors as wellas on RJ-45 (and RJ-11) style connectors. Thus, it will be appreciatedthat the “plug” referred to in the description above may comprise, forexample, a fiber optic connector that is mounted on the end of a fiberoptic patch cord. Additionally, in some embodiments, the plug may notactually be inserted directly between the structures 302′, 304′.Instead, the structures 302′, 304′ may be positioned so that when theplug is inserted into the plug aperture the plug comes close to thestructures 302′, 304′, but does not actually end up between thestructures (or is only partially between the structures). As long as theplug comes relatively close to the structures 302′, 304′, it will cause“fringe” effects that change the capacitance between the structures302′, 304′ in a manner that can be detected.

FIGS. 21A-21B are schematic diagrams that illustrate a jack 300-3 thatincludes yet another plug insertion/removal detection circuit 700-3according to embodiments of the present invention. In particular, FIG.21A is a schematic front view of the jack 300-3 with no plug insertedtherein, and FIG. 21B is a top schematic view of two electrodes 1104,1108 that form a capacitor when a plug is inserted within the plugaperture of jack 300-3. The plug detection circuit 700-3 may be coupledto the phantom mode transmitter 270 and the phantom mode receiver 260 inthe same manner, discussed above with reference to FIG. 10C, that plugdetection circuit 700-1 is coupled to the phantom mode transmitter 270and the phantom mode receiver 260.

As shown in FIGS. 21A-21B, the plug insertion/removal detection circuit700-3 comprises a hinged flap mechanism 1102 that includes a plateportion 1104 and a hinge 1106. The hinged flap mechanism 1102 may bespring loaded by a spring (not shown) that contacts the back surface ofplate portion 1104. The hinge 1106 may comprise any suitable hingestructure including one piece hinges that are formed using a resilientand/or flexible material. The hinge 1106 may be used to move the plateportion 1104 between a resting position (which is the positionillustrated in FIG. 21A) and an activated position in which the plateportion 1104 is rotated 90 degrees backwards into the plug aperture(such that the plate portion 1104 would no longer be visible in FIG.21A). The reverse side of plate portion 1104 (i.e., the major surface ofplate 1104 that is not visible in FIG. 21A) may be coated with aconductive material such as copper. The plug insertion/removal detectioncircuit 700-3 further comprises a conductive plate 1108. The conductiveplate 1108 is positioned so that it is parallel to and slightly spacedapart from plate portion 1104 when plate portion 1104 is in itsactivated position. The plate portion 1104 and the conductive plate 1108may form the electrodes of a capacitor. The plate portion 1104 and theconductive plate 1108 may be coupled to the phantom mode transmitter 270and the phantom mode receiver 260 by any suitable electrical connections(not shown) so that a signal may be transmitted through the capacitorformed by plate portion 1104 and the conductive plate 1108.

The plug insertion/removal detection circuit 700-3 may operate asfollows. When no plug is present in the plug aperture of jack 300-3, theplate portion 1104 of hinged flap mechanism 1102 will be biased by thespring (not shown) in its resting position. When an out-of-band controlsignal is transmitted from the phantom mode transmitter 270 to thephantom mode receiver 260 through the capacitor formed by plate portion1104 and the conductive plate 1108 the received signal will be very weak(if even detectable), since the electrodes 1104, 1108 of the capacitorwill be positioned at a 90 degree angle with respect to each other, andhence very little signal energy will couple from electrode 1104 toelectrode 1108. In contrast, when a plug is inserted into the plugaperture, the front portion of the plug housing forces the plate portion1104 to rotate backwardly 90 degrees into the plug aperture into itsactivated position. When this occurs, as shown in FIG. 21B, the plateportion 1104 is located parallel to, and directly below, the conductiveplate 1108 so that plates 1104 and 1108 will operate like a conventionalplate capacitor. When plate portion 1104 is in this activated position,the coupling between electrodes 1104 and 1108 will be significantlygreater than the coupling that occurs between these two electrodes whenplate portion 1104 is in its resting position. The phantom mode receiver260 may sense this difference in received signal strength and interpretthis difference as meaning that a plug has been inserted into the plugaperture of jack 300-3.

FIGS. 22A-22B are schematic diagrams that illustrate a jack 300-4 thatincludes a plug insertion/removal detection circuit 700-4 according tostill further embodiments of the present invention. The pluginsertion/removal detection circuit 700-4 is quite similar to the pluginsertion/removal detection circuit 700-3 discussed above. FIG. 22A is aschematic front view of the jack 300-4 with no plug inserted therein,and FIG. 22B is a top schematic view of two electrodes 1110, 1112 that,in conjunction with plate portion 1104, form a capacitor when a plug isinserted within the plug aperture of jack 300-4. The plug detectioncircuit 700-4 may be coupled to the phantom mode transmitter 270 and thephantom mode receiver 260 in the same manner, discussed above withreference to FIG. 10C, that plug detection circuit 700-1 is coupled tothe phantom mode transmitter 270 and the phantom mode receiver 260.

As shown in FIGS. 22A-22B, the plug insertion/removal detection circuit700-4 comprises a hinged flap mechanism 1102 that may be identical tothe hinged flap mechanism 1102 discussed above with respect to FIGS.21A-21B, and hence further description thereof will be omitted. The pluginsertion/removal detection circuit 700-4 further comprises a pair ofconductive plates 1110, 1112 that replace the conductive plate 1108 ofplug insertion/detection circuit 700-3 of FIGS. 21A-21B. The conductiveplates 1110, 1112 are positioned adjacent to each other in the sameplane, and serve as the two electrodes of a capacitor. The conductiveplates 1110, 1112 may be coupled to the phantom mode transmitter 270 andthe phantom mode receiver 260 by any suitable electrical connections(not shown) so that a signal may be transmitted through the capacitorformed by plates 1110 and 1112.

The plug insertion/removal detection circuit 700-4 may operate asfollows. When no plug is present in the plug aperture of jack 300-4, theplate portion 1104 of hinged flap mechanism 1102 will be biased by thespring (not shown) in its resting position. When an out-of-band controlsignal is transmitted from the phantom mode transmitter 270 to thephantom mode receiver 260 through the capacitor formed by the conductiveplates 1110, 1112, the received signal will be very weak (if evendetectable), since the electrodes 1110, 1112 of the capacitor, whilelocated adjacent to each other, are positioned end-to-end and hence willonly exhibit fringe coupling. In contrast, when a plug is inserted intothe plug aperture, the front portion of the plug housing forces theplate portion 1104 to rotate backwardly 90 degrees into the plugaperture into its activated position. When this occurs, as shown in FIG.22B, the plate portion 1104 is located parallel to, and directly below,the adjacent conductive plates 1110, 1112. Consequently, significantcapacitive coupling will occur between plate 1104 and plate 1110 andbetween plate 1104 and plate 1112. Thus, an out-of-band control signalthat is transmitted from the phantom mode transmitter 270 to the plate1110 will capacitively couple to plate portion 1104, and may thencapacitively couple from plate portion 1104 to plate 1112 where it iscarried to the phantom mode receiver 260. Thus, when plate portion 1104is in its activated position, the coupling between electrodes 1110 and1112 will be significantly greater than the coupling that occurs betweenthese two electrodes when plate portion 1104 is in its resting position.The phantom mode receiver 260 may sense this difference in receivedsignal strength and interpret this difference as meaning that a plug hasbeen inserted into the plug aperture of jack 300-4.

While the plug insertion/removal detection circuits 700-3 and 700-4 arepositioned in the top of the jacks 300-3 and 300-4, it will beappreciated that in other embodiments, these circuits could bepositioned elsewhere within the plug aperture. It will likewise beunderstood that components other than the phantom mode transmitter 270and the phantom mode receiver 260 could be used to transmit the sensingsignal through the various plug insertion/removal detection circuitsdescribed above. It will also be appreciated that the pluginsertion/removal detection circuits 700-3 and 700-4 illustrated withrespect to FIGS. 21A-22B may be used with both copper patch cords andfiber optic patch cords. It will also be appreciated that the hingedflap mechanism 1102 that is included in these circuits may be mounted onthe housing of the jack or, alternatively, may be mounted on anotherstructure such as face plate for a wall jack or a printed circuit boardfor an intelligent patch panel.

Method of detecting the insertion and/or removal of a plug from acommunications connector according to further embodiments of the presentinvention will now be described with reference to the flow chartdiagrams of FIGS. 19-20.

As shown in FIG. 19, operations for one of these methods may begin witha control signal being received that was electromagnetically coupledthrough a reactive coupling element of the communications connector(block 1020). This received control signal may then be analyzed (block1025). If this analysis determines that one or more criteria are met(block 1030), then a determination may be made that a mating plug hasbeen inserted into the plug aperture (block 1035). The criteria maycomprise, for example, a signal strength of the received control signalmeeting a threshold or merely the detection of the presence of thereceived control signal.

In some embodiments, the reactive coupling element may be a capacitorthat has a first electrode that is mounted adjacent a first side of theplug aperture (e.g., a side wall or a top surface) and a secondelectrode that is mounted adjacent a second side of the plug aperture(e.g. the other side wall or the bottom surface), where the second sideis opposite the first side. In some embodiments, the connector may be anRJ-45 jack that has a plurality of spring contacts, and the first andsecond electrodes may be mounted such that the plurality of springcontacts are not positioned between the first and second electrodes whenthe plurality of spring contacts are in their respective restingpositions, and portions of the plurality of spring contacts arepositioned between the first and second electrodes when the mating plugis received within the plug aperture.

The flow chart of FIG. 20 illustrates methods of detecting pluginsertions into a plug aperture of a communications jack according tostill further embodiments of the present invention. As shown in FIG. 20,operations may begin with the transmission of a plug insertion detectionsignal to a plug insertion detection circuit that includes a switch thatselectively opens and closes the plug insertion detection circuit (block1040). Thereafter, a determination is made as to whether or not the pluginsertion detection signal has been received at a receiver (block 1045).If it has not, operations return to block 1040. If the plug insertiondetection signal is received at the receiver at block 1045, then it maybe determined that the plug is present within the plug aperture (block1050).

In some embodiments of these methods, the plug insertion detectioncircuit may include a capacitor that capacitively couples the pluginsertion detection signal onto at least a first conductor of a firstdifferential pair of conductive paths through the communications jack.Moreover, the switch may be a spring contact and a mating contact pad,where the contact pad is positioned so that insertion of a mating plugwithin the plug aperture resiliently deflects the spring contact intophysical and electrical contact with the contact pad.

It will be appreciated that in further embodiments of the presentinvention a variety of other plug insertion/removal detection circuitsmay be used other than the exemplary circuits 690, 700-1 and 700-2 thatare described above. By way of example, in other embodiments, pluginsertions and/or removals may be detected using infrared emitters anddetectors that are provided across each plug aperture or through the useof a combined infrared emitter/detector that detects the presence orabsence of a reflected infrared signal, both of which techniques aredisclosed, for example, in the above-referenced U.S. patent applicationSer. No. 12/787,486 and in U.S. Pat. No. 6,424,710. Likewise, in stillfurther embodiments, the plug insertion/removal detection circuit may beimplemented using, for example, optical emitters and detectors, magneticdetectors, mechanical and/or electromechanical switches and the likethat are triggered when plugs are inserted into, or removed from, thejack 600. However, the exemplary circuits 690, 700-1 and 700-2 that aredescribed above may be advantageous in certain embodiments as the addedcost per connector port may be very small when such circuits are addedto devices that already include phantom mode control signallingcircuitry (or other circuitry that may be used to transmit and receive asignal that capacitively couples through the plug aperture).

One potential advantage of including plug insertion/removal detectioncircuits on some or all of the connector ports of a channel is that itpermits the intelligent tracking system to operate as an event-drivensystem. In particular, instead of performing periodic scans to determineall patching connections in a communications network, the system canmonitor for plug insertions and/or removals and only send common modeand/or phantom mode control signals after the detection of such pluginsertions and removals to update the connectivity information. In someembodiments, connectivity information could be tracked and updated usingboth event driven signalling and periodic scans that may be performed ona less frequent basis.

A simplified, exemplary method by which an event driven scan may beperformed will now be discussed with reference to FIG. 12, which is aschematic block diagram of two patch panels 200-1, 200-2 that are partof a cross-connect communications patching system 720.

As shown in FIG. 12, the patch panels 200-1, 200-2 each include aplurality of connector ports 220 (only a single connector port 220-1,220-2 is shown on the respective patch panels 200-1, 200-2 in FIG. 12 tosimplify the drawing). Additionally, each of the patch panels 200-1further includes a phantom mode transmitter 260, a processor 280 and aphantom mode receiver 270. A patch cord 730 having plugs 731, 732 oneither end thereof is used to interconnect connector port 220-1 of thefirst patch panel 200-1 with connector port 220-2 of the second patchpanel 200-2. For purposes of this example, it will be assumed that theconnector ports 220-1, 200-2 are each implemented using the jack 600described earlier herein.

When the plug 731 on patch cord 730 is inserted into connector port220-1 (which, as noted above, is assumed to have the design of jack 600of FIG. 9) of the first patch panel 200-1, the plug will deflect thespring contacts 341-348 of connector port 220-1 downwardly, driving theminto direct physical contact with the corresponding contact pads351-358. A phantom mode control signal is periodically transmitted fromthe phantom mode transmitter 260 to the connector port 220-1. If a plugis present in the connector port 220-1, this phantom mode signal iscapacitively coupled via plates 360, 370 onto contact pads 351-352 and357-358, from which it is coupled onto the signal carrying paths thoughconnector port 220-1. Thus, when plug 731 is inserted into connectorport 220-1, the relevant component of the phantom mode control signalfrom phantom mode transmitter 260 (i.e., the positive or negativecomponent of the phantom mode control signal) will appear on contactingstructure 696 which feeds this signal to the phantom mode receiver 270and/or microprocessor 280 on patch panel 200-1. A comparison or analysisis performed on this signal (see above discussion) and, based on thatcomparison/analysis, a determination is made that a plug has beeninserted into the connector port 220-1. The microprocessor 280 may thennotify its associated rack manager 36 (see FIG. 2) that a patch cord hasbeen plugged into connector port 220-1.

Once the plug 731 is inserted into connector port 220-1, the phantommode control signal which is being periodically injected into connectorport 220-1 by phantom mode transmitter 260 will be injected onto thepatch cord 730 via the plug 731, and will travel down the conductors ofpairs 2 and 4 of the patch cord 730. Once the plug 732 on the far end ofthe patch cord is plugged into the connector port 220-2 on the secondpatch panel 200-2, the injected phantom mode control signal will travelfrom the blades of the plug 732 onto the spring contacts 341-348 of theconnector port 220-2 on the second patch panel 200-2. This phantom modecontrol signal may be capacitively coupled onto the plates 360, 370 ofthe connector port 220-2, and is then coupled to the phantom modereceiver 270 on the second patch panel 200-2, where it is demodulated toprovide a digital data stream. This data stream includes a uniqueidentifier that identifies the first patch panel 200-1 and the connectorport 220-1 thereof that plug 731 is plugged into. The microprocessor 280on the second patch panel 200-2 already knows the unique identifierassociated with the connector port 220-2 that plug 732 is plugged into,and hence it may then pass to its associated rack manager 36 (see FIG.2) the unique identifiers of the two connector ports 220-1, 220-2 thatare connected by the patch cord 730 for logging in a database or tableof patch cord connections. In this fashion, the insertion of a plug intoa connector port may automatically result in an update to theconnectivity database.

The above example that is described with reference to FIG. 12illustrates how patching connections may be automatically trackedbetween two connector ports. It will be appreciated that the connectorports may be patch panel connector ports, network switch connectorports, modular wall jack connector ports (or other work area outlets) sothat patch cord or horizontal cabling connections can likewise beautomatically tracked between these additional devices.

Another capability that is enabled by providing plug insertion/removaldetection circuits is the ability to detect and track plug insertionsand/or removals in the work areas of a commercial office building and/orin data centers. By tracking such insertions and/or removals networkadministrators may be able to detect potential security breaches and/orresolve problems remotely. For example, if a plug on a patch cord thatconnects a user's computer to a modular wall jack becomes loose, theuser may report computer problems to a network administrator. Thenetwork administrator may consult a log and see that the system detecteda plug removal when the plug loosened from the connector port on thecomputer. By automatically gathering this information, the system maymake it easier for network administrators to resolve various problems.

One issue with extending the phantom mode control signalling capabilityto the work areas is that the phantom mode transmitter, the phantom modereceiver and/or the processor that is used to transmit and/or receivesuch signals generally require power to operate. Typically, such powerwill not be readily available at all modular wall jacks and otherconnector ports throughout the work areas. Accordingly, in someembodiments of the present invention, power-over Ethernet techniques maybe used to provide a power signal to each work area connector port inorder to provide power to the phantom mode control circuit elementsincluded at the connector port. In other embodiments, the work areaconnector ports could be located in close proximity to standard 110-voltalternating current power outlets and power could be inductively coupledfrom the alternating current power lines that are connected to thesepower outlets. In still other embodiments, power could be wired directlyto each work area connector port or, alternatively, batteries could beprovided at each connector port that provide the necessary operatingvoltage. In still further embodiments, the phantom mode control signalcould be sent continuously, and a rectifier could be included at theconnector port that uses the received signal to charge a capacitor thatpowers the phantom mode control signalling circuitry. Thus, it will beappreciated that power could be provided to the work area connectorports in a variety of different ways.

As discussed above with respect to FIGS. 8A-8D, in addition to trackingcable and patch cord connections, embodiments of the present inventionalso may provide capabilities for tracking work area and/or network enddevices. In particular, when an interposer 500 (see FIGS. 8A-8D) ismounted on an end device, in some embodiments, the microprocessor 580that is included on the interposer 500 may be programmed with the MAC IDof the end device or other identifying information, and themicroprocessor 580 may further be programmed to include this identifyinginformation in the phantom mode control signals that are generated bythe interposer 500 and transmitted onto the phantom mode controlchannel. As the manner in which an interposer 500 may send a phantommode control signal to a system manager or other controller has beendescribed above, a description of this process will be omitted here forthe sake of brevity. The relevant point is that interposers 500 that aremounted on, for example, work area end devices may use the same processto provide information to the system manager, thereby allowing thesystem manager to track end-to-end connectivity information for eachchannel. As discussed below, this end-to-end information may be used fora variety of purposes such as enhanced network security.

FIG. 13 is a flow chart illustrating a method of automaticallyidentifying an end device that is connected to a communications networkaccording to certain embodiments of the present invention. As shown inFIG. 13, operations may begin with an interposer being mounted within aconnector port of an end device (block 740). The interposer may includea plug end that mounts within a connector port on the end device and ajack end that is configured to receive a patch cord. Next, adetermination may be made as to whether or not a patch cord has beenconnected (i.e., plugged into) the interposer (block 745). This may beaccomplished, for example, using any of the above-described pluginsertion/removal detection circuits. If at block 745 it is determinedthat a patch cord has not been connected to the interposer, thenoperations proceed back to block 745 where the system may continue tomonitor for a plug insertion into the interposer. If instead at block745 it is determined that a patch cord has been connected to theinterposer, then operations may proceed to block 750, where a phantommode control signal may be transmitted from the interposer to aconnector port on a patch panel of the communications network over aphantom mode control channel that runs from the interposer to theconnector port on the patch panel. The phantom mode control signal mayinclude identifying information for the end device. This identifyinginformation may be accumulated in a central database that tracks the enddevices that are connected to each channel in the communicationsnetwork.

The above-discussed identifying information for end devices such as workarea end devices that may be collected according to embodiments of thepresent invention may also be used to perform network securityoperations. By way of example, a system manager or other controlprocessor could monitor some or all of the work area end devices thatare connected to a network and make sure that those end devices onlyhave access to appropriate network equipment, services, virtual localarea networks and the like. However, one potential problem with usingthe interposers 500 for such network security applications is that userscould remove an interposer 500 from a first work area end device (e.g.,a corporate computer that is authorized access to the network) and thenplace the interposer 500 on another device (e.g., an employee's personallaptop computer that is not authorized access to the network). Thus, solong as such unauthorized use of the interposers 500 is readilypossible, it may be difficult to use the interposers 500 to implementnetwork security techniques. However, pursuant to further embodiments ofthe present invention, the plug portion of the interposers 500 mayinclude a locking mechanism that a network administrator may use to lockthe interposer 500 into a connector port on an end device. This lockingmechanism may be designed such that it is difficult (or impossible) forsomeone without an unlocking key to remove the interposer 500 from anend device without damaging the interposer 500 and rendering itinoperable. In this fashion, unauthorized use of the interposers 500 maybe made difficult, allowing the interposers 500 to be used to provideenhanced network security.

In some embodiments, the plug end of the interposer may be provided witha locking mechanism such as the locking mechanisms disclosed in U.S.Patent Application Publication No. 2010/0136809. In such embodiments,the microprocessor 580 could be embedded in the locking mechanism insuch a way that anyone breaking the locking mechanism to remove theinterposer 500 would also break the electrical connection between themicroprocessor 580 and the remaining circuitry of the interposer 500.

As noted above, using the interposers 500 to automatically discover theMAC IDs (or other identifying information) of end devices that connectto a network may allow for enhanced security procedures. In particular,in current communications systems, MAC ID filtering is sometimes used toprevent unauthorized access of end devices to the network. With MAC IDfiltering, a connector port on a network switch may be configured toonly allow MAC IDs within a certain range to have access to the switchconnector port. If an end device having a MAC ID outside of theauthorized range attempts to connect to the network via the switchconnector port, the connector port automatically shuts down and a systemadministrator is notified. The system administrator may then determinewhether or not the end device should be given access to the network, andmay reprogram the connector port on the switch to accept the MAC ID ofthe end device if the end device should be allowed access. Networkaccess control technology may also be used instead of MAC filtering toenforce corporate network security policies for access to a network.

As discussed above, pursuant to embodiments of the present invention, itmay be possible to automatically identify the MAC ID of end devices thatare connected to a network using phantom mode control signals andinterposers 500. In some embodiments, the network switches that are notin use could be set to a disabled state. When the system discovers thata new end device has been connected to the network, the system candetermine the MAC ID of the end device and compare that MAC ID to a listof approved devices. If the MAC ID is included on the approved list, thesystem may then automatically enable the switch port, thereby providingthe end device access to the network. In this manner, the network couldautomatically only provide access to approved devices, providingenhanced network security as compared to current MAC ID filtering ornetwork access control techniques. In some embodiments, the connectorport at the network switch will only be automatically enabled if the MACID of the end device is on an authorized list of MAC IDs. In otherembodiments, the switch port may be automatically enabled for any enddevice having an interposer that provides phantom mode control channelsignalling capabilities, regardless of the specific MAC ID of the enddevice. The ability to only enable a particular connector port on anetwork switch upon detecting that an end device has been connected tothe connector port (through cabling and intermediate jacks) may alsoresult in power savings, particularly in the data center environment.

Moreover, since the system can track the MAC IDs or other identifyinginformation associated with the end devices, this identifyinginformation may be used to restrict the access of certain devices toparticular resources within the network. The MAC IDs or otheridentifying information that are transmitted by end devices over thephantom mode control channel may also be used to identify a specificservice that needs to be provided to a connected device. The systemcould automatically be reconfigured to assign the required service tothe switch port to which the end device is connected. By way of example,an Internet telephone typically requires access to Voice Over InternetProtocol (“VOIP”) service. Upon detecting by, for example, by a MAC ID,that an Internet telephone has been connected to a particular switchport, the system can cause a virtual local area network (“VLAN”) toprovision VOIP service to the identified switch port. Thus, byautomatically tracking the MAC IDs of end devices, the system can beconfigured to automatically provision certain services to connectorports on network switches in response to end devices being connected tothe network, thereby avoiding the need to manually perform suchprovisioning operations.

By way of example, the flow chart of FIG. 14 illustrates a method ofoperating a network switch according to certain embodiments of thepresent invention. As shown in FIG. 14, operations may (optionally)begin with a plug insertion detection circuit being used toautomatically detect that a first end device is connected to a first endof a first channel that runs through a first of the connector ports onthe network switch (block 900). A determination may then be made as towhether or not the first end device is within a set of authorized enddevices (block 905). In some embodiments, this determination may be madeusing a phantom mode control channel to determine a first identifierthat is associated with the first end device and then determining if thefirst identifier is within a set of authorized identifiers (e.g.,determining that a MAC ID of the first end device is within a set ofauthorized MAC IDs). In other embodiments, this determination may bemade simply by the fact that the first end device includes a phantommode control channel. If at block 905 it is determined that the firstend device is not within a set of authorized end devices, operations mayend. If at block 905 it instead is determined that the first end deviceis within the set of authorized end devices, then the first of theplurality of connector ports may be enabled (block 910).

In some embodiments, once the connector port is enabled (or beforeenabling, in some embodiments), a service that is to be provided to thefirst end device may then be identified based at least in part on thefirst identifier (block 915). The network may then be automaticallyreconfigured to provision the identified service to the first channel(block 920).

As discussed above, pursuant to embodiments of the present invention,various methods of identifying connectivity in a communications networkare provided. The flow chart of FIG. 15 illustrates one such exemplarymethod. As shown in FIG. 15, operations may begin with a phantom modecontrol signal being transmitted from a connector port on a networkswitch to a connector port on a patch panel via a patch cord thatextends therebetween (block 930). The phantom mode control signalincludes a unique identifier that is associated with the connector porton the network switch, and may be transmitted over at least twodifferential pairs of conductors of the patch cord. Next a firstcomponent of the phantom mode control signal is coupled to a phantommode control signal receiver via a first capacitor included in theconnector port of the patch panel (block 935). A second component of thephantom mode control signal is likewise coupled to the phantom modecontrol signal receiver via a second capacitor that is included in theconnector port of the patch panel (block 940). The unique identifierassociated with the connector port on the network switch may then beextracted from the phantom mode control signal at the patch panel (block945). Finally, the connection between the connector port on the networkswitch and the connector port on the patch panel may be logged in aconnectivity database (block 950).

According to still further embodiments of the present invention, thephantom mode control signalling techniques and equipment disclosedherein may be used to map the horizontal cabling for a communicationsnetwork. If the work area outlets include phantom mode controlsignalling capability, then such capabilities may be used toautomatically map the horizontal cabling topology at the time thecabling is installed.

For example, referring back to FIG. 3, a communications system 100 isdepicted that connects a network switch 130 to a plurality of wall jacks140. As shown in FIG. 3 with respect to one exemplary wall jack 140,each wall jack 140 may include a phantom mode transmitter, a processorand/or a phantom mode receiver. These capabilities may be used toautomatically map the connections of the horizontal cables 144 thatconnect the modular wall jacks 140 to the connector ports 111-114 on thefirst patch panel 110 to confirm that each horizontal cable 144 has beenconnected to the intended ones of the connector ports 111-114. Toaccomplish this, the microprocessor 116 on patch panel 110 may instructeach microprocessor 144 on the modular wall jacks 140 to send a phantommode control signal with the identifying information for the wall jack140 (e.g., office and outlet number). When each wall jack 140 receivesits respective control signal, it responds by sending a responsivecontrol signal back over the phantom mode control channel that includesthe identifying information for the wall jack 140. This information maythen be compared to a desired topology to determine if the horizontalcabling was correctly installed. In some embodiments, it may benecessary to have patch cords plugged into each connector port 111-114on the patch panel 110 in order to map the horizontal cabling since theplugs of the patch cords push the contact wires of the connector ports111-114 into mechanical and electrical contact with correspondingcontact pads that are used to couple the phantom mode control signalonto the channel.

According to still further embodiments of the present invention, thephantom mode control signalling techniques and equipment disclosedherein may be used to map a communications cabling network before patchcords are plugged in at either end of the network. In particular, afterthe horizontal cabling for a communications network has been installed,it may be desirable to automatically map the topology of the horizontalcabling. In many situations, it may be desirable to perform this mappingbefore end devices or network switches have been connected to thenetwork.

In particular, as discussed above with respect to FIG. 9, jacksaccording to certain embodiments of the present invention may include aplug insertion/removal detection circuit 690 that includes an externallyaccessible contacting structure 696 that is electrically connected toone of the conductive paths of a first of the differential pairs ofconductive paths through the jack. As is also mentioned above, thesejacks may further include a second externally accessible contact 692′, asecond conductive trace 694′ and a second contacting structure 696′ thatare electrically connected to one of the conductive paths of a second ofthe differential pairs of conductive paths through the jack. Thesestructures may provide a pair of electrical paths that may be used totransmit a differential (non-phantom mode) control signal from, forexample, a patch panel connector port to a wall jack. This differentialcontrol signal may be used to discover the connection between the patchpanel connector port and the wall jack even if no patch cords have yetbeen connected to the patch panel.

A transmitter on the patch panel (or alternatively, a transmitter on ahandheld device, a rack manager, etc.) may be electrically connected tothe externally accessible contacts 696, 696′ so that the differentialcontrol signal may be injected onto two of the conductive paths of thehorizontal cable extending between the patch panel connector port andthe wall jack. In some embodiments, the same transmitter may be usedthat is used to generate the phantom mode control signals (e.g.,transmitter 115 of FIG. 3), although it may be necessary to suitablymultiplex the different signals generated by the transmitter to deliverthese signals to the appropriate contact structures. The externallyaccessible contacts 696, 696′ that are similarly provided on eachmodular wall jack may be used to couple the differential control signaloff of the channel and to pass that signal to a receiver of the walljack. In response to receiving the differential control signal, theprocessor at the wall jack may cause a transmitter at the wall jack togenerate a responsive differential control signal that may be similarlyinjected onto the horizontal, cable using the contact structures 696,696′ of the wall jack. This responsive differential control signal maybe extracted from the horizontal cable at the patch panel connector portusing the contact structures 696, 696′ thereof, where it may be passed,for example, via a multiplexer to a receiver mounted on the patch panel.The responsive differential control signal may include identifyinginformation for the modular wall jack which may be used to ascertainwhich wall jack the patch panel connector port has been connected to.Thus, it will be appreciated that the externally accessible contacts696, 696′ that may be provided on the patch panel connector ports andmodular wall jacks according to certain embodiments of the presentinvention may be used to map the horizontal cabling connections evenbefore any patch cords are connected in the communication system.

It should be noted that any differential control signal that is injectedonto a channel using the contacting structures 696, 696′ may interferewith any underlying traffic signals that are being carried on thevarious differential pairs of the channel. Accordingly, in someembodiments, a plug insertion/detection circuit may be used to confirmthat no plug is plugged into the patch panel connector port and/or themodular wall jack before the differential control signal is injectedinto the channel.

Pursuant to still further embodiments of the present invention, thephantom mode control signalling capabilities that are disclosed hereinmay be used to carry control signals that are unrelated to thecommunications network. These capabilities are described with respect toFIGS. 16 and 17. In particular, FIG. 16 is a schematic diagramillustrating the different low voltage wiring that may be provided to atypical office in a commercial building to support various buildinginfrastructure systems. FIG. 17 illustrates how the phantom mode controlsignals according to embodiments of the present invention may be used toreduce the amount of wiring that is necessary.

Turning first to FIG. 16, it can be seen that as many as five differenttypes of cables may run to a given office in a commercial officebuilding. These cables include (1) Ethernet communications cables, suchas the cables discussed above in the present disclosure, (2) pagingcables for a paging system, (3) security cables that carry signals for asecurity system (e.g., cameras), (4) lighting control cables that carrycontrol signals for intelligent lighting systems, and (5) control cablesfor heating and air conditioning controls (“HVAC cables”) such as thewires that run to thermostats. Low-voltage cables may also be providedfor other and/or additional building infrastructure systems. Typicallythe paging cables, the security cables, the lighting control cables andthe HVAC cables are implemented using thin copper wires that are similarto speaker wires. The need to run such a large number of cables—oftenover long distances—into many if not most offices in a commercialbuilding can greatly increase both the material costs and constructioncosts of the building. FIG. 16 schematically illustrates how a long“horizontal” run may be required for each different type of cabling towire the cable into each office (the cables that extend to a singleoffice are shown in FIG. 16 in order to simplify the drawing).

Pursuant to further embodiments of the present invention, the phantommode control channels that are present on the Ethernet cables in thecommunications systems disclosed herein may be used to reduce the amountof low voltage cabling required. In particular, as illustratedschematically in FIG. 17, the control systems for the paging system, thesecurity system, the lighting system (e.g., a control system thatautomatically turns lights on and off based on certain criteria such astime of day, the sensed presence of certain individuals within abuilding, etc.) and the HVAC system may be located in or near thecomputer room for the building. A decoder/extractor unit 960 (which mayalso be referred to herein as a “distributor” unit) is located in thecomputer room, and a first set of short cables may connect each of thelighting control system, the HVAC control system, the paging system, thesecurity system to the decoder/extractor unit 960. A short Ethernetcommunications cable may also run to the decoder/extractor unit 960.Consolidator/encoder units 965 (only one is shown in FIG. 17) may beadded in selected locations in the work areas throughout the building. Alonger Ethernet communications cable may run from the decoder/extractorunit 960 to a consolidator/encoder unit 965 that may be located, forexample, in or adjacent to one of the offices in the building. A secondset of short cables may run from the consolidator/encoder unit 965 intothe office to provide the control signals to the various systems.

In operation, the control signals that are to be sent to remote units ofthe paging system, the security system, the lighting system and the HVACsystem that are located in a particular office are generated by theappropriate systems in the computer room and then are provided to thedecoder/extractor 960 which multiplexes these signals onto the phantommode control channel of an Ethernet communications cable that islikewise being sent to the office at issue. The decoder/extractor unit960 may include a connector port that receives a short Ethernet cablefrom, for example, one of the connector ports on a patch panel. Thisconnector port at the decoder/extractor unit 960 may include a controlsignal input circuit such as the circuit provided on jack 300 discussedabove, and the decoder/extractor unit 960 may further include phantommode control signalling circuitry that may be used to inject a phantommode control signal into the Ethernet channel (in other embodiments, acommon mode signal may be used that is transmitted over one or more ofthe differential pairs of the Ethernet cable). The decoder/extractorunit 960 may receive control signals from the various systems (e.g.,paging, security, etc.), process these (if necessary) into anappropriate format, and then multiplex these systems onto the phantommode control channel in order to transmit the signals to theconsolidator/encoder unit 965. Any appropriate multiplexing scheme suchas, for example, time division multiplexing may be used to multiplexmultiple control signals onto each phantom mode control channel.

The consolidator/encoder units 965 in the individual offices may havephantom mode control circuitry that may be used to extract the phantommode control signal from the phantom mode control channel and thendemultiplex the phantom mode control signal to extract the individualcontrol signals for the security system, the paging system, the lightingsystem and/or the HVAC system. The system may also be designed to allowfor two way communications over the phantom mode control channel. Thus,it will be appreciated that in some embodiments the decoder/extractorunit 960 and the consolidator/encoder unit 965 may be identical unitsthat consolidate a plurality of control signals and transmit them over aphantom mode control channel and may also extract a plurality of controlsignals from a phantom mode control channel and route each signal to itsappropriate location.

Thus, pursuant to embodiments of the present invention, the phantom modecontrol channels may be used to reduce the amount of non-Ethernetcabling required in commercial office buildings. While short cablingruns may be required to connect the security system, the paging system,the lighting control system and the HVAC system to the decoder/extractorunit 960 and to run from the consolidator/encoder unit 965 into eachindividual office, the long horizontal cabling runs for these differentcontrol systems, an exemplary one of which is illustrated in FIG. 16,may be eliminated through the use of the phantom mode control channel onthe Ethernet communications cable.

In some embodiments, the consolidator/encoder unit 965 may beimplemented as part of the modular wall jacks that are provided inoffices and other rooms of most commercial office buildings. Theconsolidator/encoder unit 965 may include the above-described phantommode control signalling circuitry that is used to receive a phantom modecontrol signal such as a phantom mode transceiver and a phantom modeprocessor, and may also include a phantom mode processor fortransmitting control information back to a central location (suchcontrol information may include both cabling or connectivity informationor control signals for the security, paging, lighting or HVAC systemssuch as, for example, a control signal indicating that a user haschanged a setting on a thermostat). The receiver and/or processor on theconsolidator/encoder units 965 may be configured to perform themultiplexing and demultiplexing of the control signals, and may feed theappropriate control signals to the short cables that extend between theconsolidator/encoder unit 965 and each of the systems in the office.

As made clear from the above discussion, pursuant to embodiments of thepresent invention, methods of distributing signals from a master unit ofa building infrastructure system to a remote unit of the buildinginfrastructure system are provided in which a signal from the masterunit is multiplexed onto a phantom mode communications path of anEthernet cable. In some embodiments, the signal may be one of aplurality of control and/or data signals for one or more buildinginfrastructure systems (other than computer systems) such as, forexample, a lighting control system, an HVAC control system, a securitysystem, a fire detection system, a wireless network system, a pagingsystem, etc., that are, for example, time division multiplexed orfrequency division multiplex onto the Ethernet cable. The multiplexedsignal may thereafter be extracted from the Ethernet cable. Theextracted signal may then be distributed to the remote unit. In someembodiments, the remote unit may be powered with power provided over theEthernet cable.

By using Ethernet cabling to replace, for example, long horizontalcabling runs for other building infrastructure systems, the installationmaterial and expense for wiring a new building and/or rewiring anexisting building can be significantly reduced. Many buildinginfrastructure systems use low data rate control and/or data signals andthus, in many instances, it may be possible to multiplex the signallingfor multiple such systems onto a common mode control channel or aphantom mode control channel that is provided on existing Ethernetcabling. Moreover, power can be provided to these systems in at leastsome instances using power supplied from the switch using conventionalPower-over-Ethernet techniques. The above-described integration ofEthernet systems and other building infrastructure systems also allowsintegrating intelligent building software (e.g., software thatautomatically controls lighting systems, HVAC systems etc. to reduceenergy usage or the like) into network management software to provide amore efficient overall solution. With such integrated systems, the pluginsertions and/or removals that may be detected using, for example, theplug insertion/removal circuits according to embodiments of theinvention could be provided to the control software for the variousbuilding infrastructure systems, thereby providing a single, integratednotification system.

While the communications patching systems and the components thereofhave primarily been described above with respect to a few exemplaryembodiments, it will be appreciated that numerous modifications are alsowithin the scope of the present invention. For example, while theillustrated connector ports inject and remove the phantom mode controlsignals from a main printed circuit board of the communicationsconnector, it will be appreciated that in other embodiments the phantommode control signal may be injected into (and/or extracted from) theconnector at other locations including, for example, from an auxiliaryprinted circuit board, an external printed circuit board that includesintelligent patching circuitry (e.g., a phantom mode transmitter orreceiver), or in the input contacts (e.g., spring contacts) or outputcontacts (e.g., IDCs) of the connector.

As another example, various of the embodiments that are discussed abovecouple the phantom mode control signal onto pairs 2 and 4 (see FIGS.5A-C) or all four pairs (see FIG. 6B). However, it will be appreciatedthat the phantom mode control signal could be coupled onto other paircombinations in other embodiments, specifically including (1) pairs 1and 3, (2) pairs 1 and 2, (3) pairs 1 and 4 and (4) pairs 3 and 4. Insuch embodiments Pairs 2 and 4 may be preferred pairs in many connectordesigns as these pairs may have fewer crosstalk and return loss issues(e.g., increased margins) and hence using these pairs to carry thephantom mode control signal may be advantageous in some connectordesigns. Combinations involving transmitting the phantom control signalonto four pairs by coupling its positive component onto two of the pairsand its negative onto the other two of the pairs are also possible, asare unbalanced pair combinations that use, for example, three of thedifferential pairs (e.g., coupling the positive component of the phantommode control signal onto pairs 2 and 4 and the negative component ontopair 1 or pair 3).

In various of the embodiments discussed above either 3-terminal or5-terminal plate capacitors are used to inject/extract the phantom modecontrol signal to and from the connector. It will be appreciated,however, that numerous other capacitive elements could be used. Forexample, in further embodiments, a vertically-oriented plate or plates(where the major plane of the printed circuit board defines a horizontalplane) could be mounted adjacent to the metal plated vias that hold thewire connection terminals for a differential pair to provide, forexample, a 3-terminal capacitor. In other embodiments, inter-digitatedfinger capacitors could be used instead of plate capacitors.

It will likewise be appreciated that any appropriate connection contactssuch as phantom mode contacts 366, 376 may be used to carry the phantommode control signal from the printed circuit board of a communicationsjack to another printed circuit board or other mounting structure thatincludes the phantom mode control signal transmitter and/or receiverand/or an intervening multiplexer, switching circuit or the like. Infact, the connection contacts 366, 376 may be implemented as anyconductive contact that electrically connects the phantom modetransmitter and/or receiver to the capacitors that are used toinject/extract the phantom mode control signal to and from theconnector. In some embodiments, the connection contact may include afirst end that has, for example, an eye-of-the-needle termination orother suitable termination that can be press-fit into a metal-platedaperture on the connector printed circuit board. The connection contactmay further include a second end that likewise has, for example, aneye-of-the-needle termination or other suitable termination that can bepress-fit into a metal-plated aperture on, for example, the patch panelprinted circuit board. In other embodiments, the second end may use aspring contact structure that electrically mates with a conductiveelement on, for example, the patch panel printed circuit board. Othermechanisms may likewise be used. Thus, it will be appreciated that thedepicted connection contacts are exemplary in nature and are notlimiting with respect to the present invention.

It will likewise be appreciated that in some embodiments, a commonprinted circuit board may be provided that serves as the printed circuitboard for each of the connectors on a multi-connector structure and thiscommon printed circuit board may likewise hold the phantom mode controlsignal circuitry. By way of example, a 24-connector port patch panelcould include a single printed circuit board that receives the springcontacts and IDCs for each connector port, the signal traces andcrosstalk compensation circuitry for each connector port, the capacitorsthat are used to inject/extract phantom mode signals from each connectorport, as well as the phantom mode transmitter, the phantom modereceiver, the processor and a multiplexer or switching circuit. In suchembodiments, the connection contacts may simply be implemented as traceson a printed circuit board.

As yet another example, it will be appreciated that in some embodimentsthe network switches that are used could be upgraded to include phantommode control signal circuitry similar to the circuitry provided on patchpanels according to embodiments of the present invention. In suchembodiments, any need for interposers according to embodiments of thepresent invention may be eliminated, as the phantom mode control signalcircuitry would be included in the switch.

While embodiments of the present invention have primarily been discussedabove with respect to tracking patching connections between two patchpanels as would be done in cross-connect communications systems andbetween a patch panel and a network, switch as would be done in aninter-connect communications system, embodiments of the presentinvention are not limited to these cases. For example, the phantom modecontrol signalling capabilities described herein can be used in avariety of other situations including identifying end devices and/ortracking horizontal cabling connections between patch panels and workarea outlets. Yet another area where the techniques of the presentinvention may be used is in tracking connections to consolidationpoints. As known to those of skill in the art, a consolidation pointrefers to a connection device that may be similar to a patch panel thatis mounted in work areas of a building such as in modular furnitureand/or work areas. The consolidation may include a plurality ofconnector ports. A plurality of horizontal cables may run from a patchpanel field in the computer room to the back end of respective ones ofthe consolidation point connector ports. Patch cords may be plugged intothe other end of each of the consolidation point connector ports. Aplurality of RJ-45-to-RJ-45 modular wall jacks may be mounted in themodular furniture and/or work areas. Each patch cord that is pluggedinto the consolidation point connector ports may run to a respective oneof these RJ-45-to-RJ-45 modular wall jacks. End devices may be connectedto each RJ-45-to-RJ-45 modular wall jack by another patch cord.

While embodiments of the present invention have primarily been discussedabove with respect to the use of phantom mode control signals, which arecontrol signals that each include two common mode signal components, itwill be appreciated that other types of control signals may be used. Forexample, as discussed above, a single common mode control signal that istransmitted over a single differential pair may be used in place of thephantom mode control signal. Likewise, multiple common mode signals(that do not together comprise a phantom mode control signal) could beused as the control signal, or a single common mode control signal couldbe used that is transmitted over multiple differential pairs. Thus, itwill be appreciated that embodiments of the present invention are notlimited to the use of phantom mode control signals.

Pursuant to embodiments of the present invention, the consolidationpoints and/or the RJ-45-to-RJ-45 modular wall jacks may include theabove-described phantom mode control signalling capabilities. In someembodiments, essentially the same equipment that is used to provide thephantom mode signalling capabilities on a patch panel may be used toprovide the capabilities to the consolidation point.

Embodiments of the present invention may have a number of distinctadvantages over prior art intelligent patching approaches. For example,some embodiments of the present invention may use conventionalcommunications cables and patch cords that do not include extraconductors, identification chips, special contacts and the like. Theinclusion of such extra elements as required by various prior artintelligent patching approaches increase the cost of the cablinginfrastructure, prevents use of the already installed cabling and patchcord base, may increase the size, weight and cost of the cabling and hasvarious other potential disadvantages. Some embodiments of the presentinvention also may require only minimal changes to the connector portsin a communications system such as, for example, the provision ofcapacitors or other capacitive elements that are used to transfer thephantom mode control signal to and from the connectors along withappropriate electrical connections to the phantom mode control signalcircuitry. Such capacitors may be implemented at almost zero cost, andthe contacts or other electrical connections may typically beimplemented as simple conductive traces or contacting structures thatadd very little to the cost of the connector. The systems according toembodiments of the present invention work in both shielded andunshielded twisted pair communications systems, and provide solutionsfor tracking of patch cord connections in both cross-connect andinter-connect communications systems.

Moreover, while the provision of the phantom mode control signalcircuitry such as the phantom mode transmitters and receivers andassociated processors may increase the cost of the systems according toembodiments of the present invention, at the patch panels, consolidationpoints and the network switches (via the use of interposers, forexample), these components may be shared across many connector portsusing multiplexers or switching circuits, and hence the overall impacton the cost of the system may be manageable. Moreover, the intelligenttracking capabilities of the communications systems according toembodiments of the present invention may extend to the work area inorder to track patch cord and cabling connections to consolidationpoints and wall jacks, and interposers or other techniques may be usedto perform tracking all the way to end devices in both the work area andthe computer room to provide full end-to-end tracking. Such tracking ofend devices may also enable a host of other capabilities such as, forexample, automatic enablement of switch ports upon detection of theconnection of an authorized device, the automatic deployment of servicesin response to detection of the connection of an authorized device, etc.Such capabilities may, for example, simplify network operation and/orprovide power savings (by allowing unused switch ports to be set to anon-enabled state).

The present invention has been described with reference to theaccompanying drawings, in which certain embodiments of the invention areshown. This invention may, however, be embodied in many different formsand should not be construed as limited to the embodiments that arepictured and described herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. It willalso be appreciated that the embodiments disclosed above can be combinedin any way and/or combination to provide many additional embodiments.

Unless otherwise defined, all technical and scientific terms that areused in this disclosure have the same meaning as commonly understood byone of ordinary skill in the art to which this invention belongs. Theterminology used in the above description is for the purpose ofdescribing particular embodiments only and is not intended to belimiting of the invention. As used in this disclosure, the singularforms “a”, “an” and “the” are intended to include the plural forms aswell, unless the context clearly indicates otherwise. It will also beunderstood that when an element (e.g., a device, circuit, etc.) isreferred to as being “connected” or “coupled” to another element, it canbe directly connected or coupled to the other element or interveningelements may be present. In contrast, when an element is referred to asbeing “directly connected” or “directly coupled” to another element,there are no intervening elements present.

Herein, the term “Ethernet cable” refers to a cable that includes atleast four twisted pairs of insulated conductors that are suitable foruse as a transmission medium for computer communications.

Certain embodiments of the present invention have been described abovewith reference to flowchart illustrations. It will be understood thatsome blocks of the flowchart illustrations may be combined or split intomultiple blocks, and that the blocks in the flow chart diagrams need notnecessarily be performed in the order illustrated in the flow charts.

In the drawings and specification, there have been disclosed typicalembodiments of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being set forth inthe following claims.

That which is claimed is:
 1. A communications connector, comprising: aplurality of input ports; a plurality of output ports; a plurality ofsignal paths, each of the signal paths connecting a respective one ofthe input ports to a respective one of the output ports, the signalpaths comprising a plurality of conductive paths that are arranged as aplurality of differential pairs of conductive paths that are eachconfigured to carry differential signals; and a control signal inputcircuit, that is separate from the plurality of signal paths andelectrically connected to at least some of the plurality of signalpaths, the control signal input circuit configured to capacitivelycouple a phantom mode control signal that includes a unique identifierthat is associated with the communications connector onto acommunications cable that is physically connected to the plurality ofinput ports via at least a first and a second of the differential pairsof conductive paths.
 2. The communications connector of claim 1, whereina positive component of the phantom mode control signal is capacitivelycoupled onto the first of the differential pairs of conductive paths viaa first capacitive circuit of the control signal input circuit, andwherein a negative component of the phantom mode control signal iscapacitively coupled onto the second of the differential pairs ofconductive paths via a second capacitive circuit of the control signalinput circuit.
 3. The communications connector of claim 2, wherein thefirst capacitive circuit comprises a first capacitor having an inputterminal and a first output terminal and a second output terminal, andwherein the second capacitive circuit comprises a second capacitorhaving an input terminal and a first output terminal and a second outputterminal.
 4. The communications connector of claim 2, wherein thecommunications connector comprises an RJ-45 jack, and wherein theplurality of input ports comprise the plug contact regions of aplurality of contacts that extend into a plug aperture of thecommunications connector, wherein the plug contact regions of the inputports that are connected to the first differential pair of conductivepaths and the plug contact regions of the input ports that are connectedto the second differential pair of conductive paths surround the plugcontact regions of the input ports that are connected to a thirddifferential pair of conductive paths and the plug contact regions ofthe input ports that are connected to a fourth differential pair ofconductive paths.
 5. The communications connector of claim 1, wherein apositive component of the phantom mode control signal is capacitivelycoupled onto the first and second of the differential pairs ofconductive paths via a first capacitive circuit of the control signalinput circuit, and wherein a negative component of the phantom modecontrol signal is capacitively coupled onto a third and a fourth of thedifferential pairs of conductive paths via a second capacitive circuitof the control signal input circuit.
 6. The communications connector ofclaim 1, wherein the positive component of the phantom mode controlsignal is capacitively coupled onto the first and second of thedifferential pairs of conductive paths via a first capacitor of thecontrol signal input circuit that has an input terminal and firstthrough fourth output terminals, and wherein the negative component ofthe phantom mode control signal is capacitively coupled onto the thirdand fourth of the differential pairs of conductive paths via a secondcapacitor of the control signal input circuit that has an input terminaland first through fourth output terminals.
 7. The communicationsconnector of claim 2, wherein the first capacitive circuit comprises afirst capacitor and a second capacitor, the first and second capacitorsincluding a conductive plate that comprises a first electrode of thefirst capacitor and a first electrode of the second capacitor, a firstcontact pad that comprises a second electrode of the first capacitor anda second contact pad that comprises a second electrode of the secondcapacitor.
 8. The communications connector of claim 7, wherein theplurality of input ports comprise a plurality of spring contacts, andwherein the first contact pad is configured to mate with a first of theplurality of spring contacts and the second contact pad is configured tomate with a second of the plurality of spring contacts.
 9. Thecommunications connector of claim 1, wherein the communicationsconnector comprises a jack having a plurality of spring contacts,wherein the jack is configured so that insertion of a plug within thejack causes transfer of the phantom mode control signal onto the springcontacts.
 10. The communications connector of claim 1, wherein thecommunications connector further includes a phantom mode transmitterthat is configured to generate the phantom mode control signal, whereinthe phantom mode control signal comprises a modulated digital signal.11. A method of providing identification information for acommunications connector, the method comprising: generating a phantommode control signal that includes a unique identifier that is associatedwith the communications connector; capacitively coupling a firstcomponent of the phantom mode control signal onto both of the conductivepaths of a first differential pair of conductive paths of thecommunications connector for communication to a remote controller; andsimultaneously capacitively coupling a second component of the phantommode control signal onto both of the conductive paths of a seconddifferential pair of conductive paths of the communications connectorfor communication to the remote controller, wherein the polarity ofsecond component is opposite the polarity of the first component. 12.The method of claim 11, wherein the phantom mode control signalcomprises a modulated digital signal.
 13. The method of claim 11,wherein the phantom mode control signal is transmitted in response todetecting that a plug has been inserted into a plug aperture of thecommunications connector.
 14. The method of claim 11, furthercomprising: capacitively coupling the first component of the phantommode control signal onto both of the conductive paths of a thirddifferential pair of conductive paths of the communications connector atthe same time that the first component of the phantom mode controlsignal is coupled onto both of the conductive paths of the firstdifferential pair of conductive paths of the communications connector;and capacitively coupling the second component of the phantom modecontrol signal onto both of the conductive paths of a fourthdifferential pair of conductive paths of the communications connector atthe same time that the second component of the phantom mode controlsignal is coupled onto both of the conductive paths of the seconddifferential pair of conductive paths of the communications connector.15. The method of claim 11, wherein the first component of the phantommode control signal is capacitively coupled onto both of the conductivepaths of the first differential pair of conductive paths of thecommunications connector via a first capacitor having an input terminal,a first output terminal and a second output terminal, and wherein thesecond component of the phantom mode control signal is capacitivelycoupled onto both of the conductive paths of the second differentialpair of conductive paths of the communications connector via a secondcapacitor having an input terminal, a first output terminal and a secondoutput terminal.
 16. A method of identifying connectivity in acommunications network, the method comprising: transmitting a phantommode control signal that includes a unique identifier that is associatedwith a connector port on a network switch to a connector port of a patchpanel of the communications network over at least two differential pairsof conductors that are included in a patch cord that connects theconnector port on the network switch to the connector port of the patchpanel; coupling a first component of the phantom mode control signal toa phantom mode control signal receiver via a first capacitive circuitincluded the connector port of the patch panel; coupling a secondcomponent of the phantom mode control signal to the phantom mode controlsignal receiver via a second capacitive circuit included the connectorport of the patch panel; extracting the unique identifier associatedwith the connector port on the network switch from the phantom modecontrol signal at the patch panel; and logging the connection betweenthe connector port on the network switch and the connector port on thepatch panel in a connectivity database.
 17. The method of claim 16,wherein the phantom mode control signal is transmitted in response todetecting that a plug has been inserted into a plug aperture of theconnector port on the network switch.
 18. The method of claim 16,wherein the first capacitive circuit comprises a first capacitor havingan input terminal, a first output terminal and a second output terminalthat is configured to couple the first component of the phantom modecontrol signal onto a first of the differential pairs of conductors thatare included in the patch cord, and wherein the second capacitivecircuit comprises a second capacitor having an input terminal, a firstoutput terminal and a second output terminal that is configured tocouple the second component of the phantom mode control signal onto asecond of the differential pairs of conductors that are included in thepatch cord.
 19. The method of claim 16, wherein the first component ofthe phantom mode control signal has a polarity that is opposite thesecond component of the phantom mode control signal.
 20. Acommunications connector, comprising: a housing having a plug aperture;a plurality of input ports; a plurality of output ports; a plurality ofconductive paths, each of the conductive paths connecting a respectiveone of the input ports to a respective one of the output ports, theconductive paths being arranged as a plurality of differential pairs ofconductive paths that are each configured to carry differential signals;and a capacitive circuit that is configured to capacitively couple asignal onto a first of the differential pairs of conductive paths, thecapacitive circuit including a conductive plate and at least two contactpads, wherein the conductive plate and a first of the at least twocontact pads forms a first capacitor and the conductive plate and asecond of the at least two contact pads forms a second capacitor. 21.The communications connector of claim 20, wherein the communicationsconnector is configured so that contact is established between a firstof the at least two contact pads and a first conductive path of thefirst of the differential pairs of conductive paths when a plug isinserted into the plug aperture.